An electronic device and a method for preparing a graphene film

Abstract

The application provides an electronic device and a preparation method of a graphene film. The graphene film comprises regions with different resistance values, can be applied to the electronic device, and can be used as a heat dissipation member of the electronic device as a whole. The low-resistance value region of the graphene film can be used as an antenna radiator. The graphene film can take into account the radiation characteristics of the antenna and the heat dissipation performance of the heat dissipation member, and effectively solves the contradiction between the two.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electronic devices, in particular to an electronic device and a preparation method of a graphene film. BACKGROUND

[0002] With the rapid development of wireless communication technology, the past second generation (2G) mobile communication system mainly supports the function of calling, and the electronic device is only a tool for people to send and receive short messages and voice communication. The wireless Internet function is extremely slow because the data transmission uses voice channels for transmission. Nowadays, in addition to being used for calling, sending short messages and taking pictures, electronic devices can also be used for online music listening, network video watching, real-time video, etc., covering various applications such as calling, video entertainment and e-commerce in people's life. Among them, many functional applications need to upload and download data through wireless networks, so high-speed data transmission becomes extremely important.

[0003] With the increasing demand for high-speed data transmission, the development trend of the industrial design (ID) of electronic devices is large screen ratio and multiple cameras. This has caused a significant reduction in antenna clearance, and the layout space is increasingly limited. At the same time, many new communication specifications have appeared, which require more antennas to be laid out in the mobile phone. The fifth generation (5G) wireless communication system also requires more and more antennas. In addition, with the increasing number of functions in electronic devices, more components need to be placed in the electronic devices, which affects the performance of the electronic devices due to the heat dissipation of the components. SUMMARY

[0004] The present application provides an electronic device and a preparation method of a graphene film. The graphene film includes regions with different resistance values and can be applied to electronic devices. The whole graphene film can be used as a heat dissipation component of the electronic device, and the low-resistance region can be used as an antenna radiator. The graphene film can balance the radiation characteristics of the antenna and the heat dissipation performance of the heat dissipation component, effectively solving the contradiction between the two.

[0005] In a first aspect, an electronic device is provided, comprising: a graphene film and a heat generating component; wherein a part of the graphene film is disposed above the heat generating component; the graphene film comprises a first region and a second region, the resistance value of the graphene film in the first region is different from the resistance value of the graphene film in the second region, or the conductivity of the graphene film in the first region is different from the conductivity of the graphene film in the second region.

[0006] According to the embodiment of the present application, the problem of mutual influence between the heat dissipation component and the radiator of the antenna structure in the electronic device is solved by multiplexing the graphene film. The graphene 110 provided by the embodiment of the present application can be used as a heat dissipation component to transfer the heat generated by the heat source (a heating device, for example, a processor, etc.) to a low heat area. Since the graphene film is a complete film, there is no interval between the first area and the second area, and the graphene film in the first area 111 and the graphene film in the second area 112 can be used as a whole graphene film, so that the heat conducted at the heat source can be uniformly distributed on the whole graphene film to achieve the purpose of cooling the overheated electronic element. At the same time, the graphene film 110 in the first area with low resistance (high conductivity) can be used as a radiator of the antenna structure to generate radiation outward.

[0007] With reference to the first aspect, in some implementations of the first aspect, the thickness of the graphene film in the first area is different from the thickness of the graphene film in the second area.

[0008] With reference to the first aspect, in some implementations of the first aspect, the graphene film in the first area and the graphene film in the second area are bonded by a heat-conducting gel.

[0009] According to the embodiment of the present application, the resistance of the graphene film in the first area and the resistance of the graphene film in the second area can be different in various ways. For example, the annealing temperature and the rolling pressure during preparation of the graphene film in the first area and the graphene film in the second area can be adjusted, or the thickness of the graphene film in the first area and the thickness of the graphene film in the second area can be adjusted, or the graphene films with two different resistances can be bonded by a heat-conducting gel to form a graphene film. The present application does not limit this, and there can be various ways to make the resistance of the graphene film in the first area and the resistance of the graphene film in the second area different.

[0010] With reference to the first aspect, in some implementations of the first aspect, the resistance of the graphene film in the first area is less than the resistance of the graphene film in the second area, or the conductivity of the graphene film in the first area is greater than the conductivity of the graphene film in the second area; and part of the graphene film in the first area is used as a radiator of the antenna structure of the electronic device.

[0011] According to the embodiment of the present application, the resistance value of the graphene film in the first region can be less than or equal to 20Ω, and the graphene film in the first region can be used as a radiator of the antenna structure. The resistance value of the graphene film in the second region 112 can be greater than or equal to 20 times of the resistance value of the graphene film in the first region, for example, 400Ω. In this case, when the graphene film in the first region is used as a radiator of the antenna structure, the graphene film in the second region can be considered as an insulating material, and the graphene film in the second region can avoid affecting the graphene film in the first region as a radiator of the antenna structure.

[0012] With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a printed circuit board (PCB), and the heat generating component is disposed on the PCB.

[0013] According to the embodiment of the present application, the heat generating component 101 can also be disposed on a flexible circuit board or a low pin count bus, and the present application does not limit this.

[0014] With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a middle frame and a back cover, the PCB and the battery are disposed in a space enclosed by the middle frame and the back cover, and part of the graphene film is disposed between the PCB and the back cover.

[0015] With reference to the first aspect, in some implementations of the first aspect, the electronic device further includes a battery, and part of the graphene film is disposed between the battery and the back cover.

[0016] According to the embodiment of the present application, part of the graphene film can be disposed between the battery and the back cover, and used as a low heat area. Part of the graphene film can also not be disposed between the battery and the back cover, and the placement position of the heat dissipating component can be changed according to the actual layout in the electronic device, and the present application does not limit this.

[0017] With reference to the first aspect, in some implementations of the first aspect, one side of the graphene film close to the middle frame is provided with an insulating layer.

[0018] According to the embodiment of the present application, one side of the graphene film close to the middle frame is provided with an insulating layer, so as to avoid short circuit between the battery or the shielding cover and the graphene film in the first region. The insulating layer can be an adhesive, for example, a heat conductive gel, which is used to make the graphene film in close contact with the heat source, and to conduct heat well.

[0019] In a second aspect, a method for preparing a graphene film is provided, including: preparing an oxidized graphene suspension, and drying the oxidized graphene suspension to obtain an oxidized graphene film; annealing the oxidized graphene film to obtain a first graphene film; and rolling the first graphene film to obtain a second graphene film including graphene films with different resistances; wherein the oxidized graphene film includes a first region and a second region, an annealing temperature of the oxidized graphene film in the first region is different from an annealing temperature of the oxidized graphene film in the second region, or a rolling pressure of the first graphene film in the first region is different from a rolling pressure of the first graphene film in the second region.

[0020] With reference to the second aspect, in some implementations of the second aspect, the rolling pressure is between 0 MPa and 600 MPz.

[0021] With reference to the second aspect, in some implementations of the second aspect, the annealing temperature is between 0℃ and 2800℃.

[0022] In a third aspect, a method for preparing a graphene film is provided, including: preparing a graphene film with a first resistance; and forming a first region and a second region on the graphene film by carving or peeling to obtain a graphene film including graphene films with different resistances, a thickness of the graphene film in the first region is greater than a thickness of the graphene film in the second region.

[0023] With reference to the third aspect, in some implementations of the third aspect, the preparing of the graphene film with the first resistance includes: preparing an oxidized graphene suspension, and drying the oxidized graphene suspension to obtain an oxidized graphene film; and annealing and rolling the oxidized graphene film to obtain the graphene film with the first resistance.

[0024] With reference to the third aspect, in some implementations of the third aspect, the preparing of the graphene film with the first resistance includes: preparing a graphene film with a second resistance, the second resistance being greater than the first resistance; and rolling the graphene film with the second resistance to obtain the graphene film with the first resistance.

[0025] In a fourth aspect, a method for preparing a graphene film is provided, including: preparing a graphene film with a first resistance and a graphene film with a second resistance, the first resistance being different from the second resistance; cutting the graphene film with the first resistance and the graphene film with the second resistance; and bonding the cut graphene film with the first resistance and the cut graphene film with the second resistance by a heat-conducting gel to obtain a graphene film including graphene films with different resistances.

[0026] In some implementations of the fourth aspect, in combination with the fourth aspect, the preparing includes: rolling the bonded graphene film to prepare the graphene film including different resistance values.

[0027] In some implementations of the fourth aspect, in combination with the fourth aspect, the rolling pressure is 300 MPa. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 FIG. 1 is a schematic diagram of an electronic device provided by an embodiment of the present application.

[0029] Figure 2 FIG. 2 is a schematic diagram of relative positions of a heat dissipation member and a patch antenna in an electronic device provided by the present application.

[0030] Figure 3 FIG. 3 is a schematic diagram of a cross section of an electronic device provided by an embodiment of the present application.

[0031] Figure 4 FIG. 4 is a schematic diagram of an electronic device provided by an embodiment of the present application. Figure 3 FIG. 5 is a schematic diagram of an electronic device provided by an embodiment of the present application.

[0032] Figure 5 FIG. 6 is a process flow diagram of a processing process of a graphene film with a low resistance value provided by an embodiment of the present application.

[0033] Figure 6 FIG. 7 is a schematic diagram of a preparation method of a graphene film provided by an embodiment of the present application.

[0034] Figure 7 FIG. 8 is a process flow diagram of a preparation method of a graphene film provided by an embodiment of the present application.

[0035] Figure 8 FIG. 9 is a schematic diagram of a structure of a graphene film provided by an embodiment of the present application.

[0036] Figure 9 FIG. 10 is a schematic diagram of a preparation method of a graphene film provided by an embodiment of the present application.

[0037] Figure 10 FIG. 11 is a process flow diagram of a preparation method of a graphene film provided by an embodiment of the present application.

[0038] Figure 11 FIG. 12 is a schematic diagram of another preparation method of a graphene film provided by an embodiment of the present application.

[0039] Figure 12 FIG. 13 is a schematic diagram of a structure of a graphene film provided by an embodiment of the present application.

[0040] Figure 13is a process flow diagram of another method for preparing a graphene film provided by an embodiment of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the present application will be described below with reference to the drawings.

[0042] It should be understood that in the present application, "electrically connected" can be understood as physical contact and electrical conduction of components; it can also be understood as a form of connection between different components through an entity line that can transmit electrical signals such as a copper foil or a wire of a printed circuit board (PCB) in a circuit structure, and it can also be understood as a coupling connection. "Communication connection" can refer to electrical signal transmission, including wireless communication connection and wired communication connection. Wireless communication connection does not require a physical medium and does not belong to a connection relationship that defines the structure of a product. "Connection" and "connected" can both refer to a mechanical connection relationship or a physical connection relationship, for example, A and B are connected or A and B are connected, which can mean that there is a fastening component (such as a screw, a bolt, a rivet, etc.) between A and B, or A and B are in contact with each other and A and B are difficult to separate.

[0043] The technical solutions provided in the present application are applicable to electronic devices using one or more of the following communication technologies: Bluetooth (BT) communication technology, global positioning system (GPS) communication technology, wireless fidelity (WiFi) communication technology, global system for mobile communications (GSM) communication technology, wideband code division multiple access (WCDMA) communication technology, long term evolution (LTE) communication technology, 5G communication technology, and other future communication technologies. The electronic device in the embodiments of the present application can be a mobile phone, a tablet computer, a notebook computer, a smart bracelet, a smart watch, a smart helmet, smart glasses, etc. The electronic device can also be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, an electronic device in a 5G network, or an electronic device in a future evolved public land mobile network (PLMN), etc. The embodiments of the present application are not limited thereto. Figure 1 An electronic device provided by the present application is exemplarily shown, and the electronic device is a mobile phone.

[0044] As shown in Figure 1 The electronic device 10 can include a cover glass 13, a display module 15, a printed circuit board (PCB) 17, a housing 19, and a rear cover 21. It should be understood that in some embodiments, the cover glass 13 can also be replaced by a cover plate made of other materials, such as a cover plate made of ultra-thin glass material, a cover plate made of PET (Polyethylene terephthalate) material, etc.

[0045] The cover glass (CG) 13 can be arranged close to the display module 15, and can be mainly used to protect the display module 15 from dust.

[0046] In an embodiment, the display module 15 can include a liquid crystal display (LCD) panel, a light emitting diode (LED) display panel, or an organic light-emitting diode (OLED) display panel, etc., which are not limited in the present application.

[0047] The printed circuit board PCB 17 can be made of a flame retardant material (FR-4) medium plate, a Rogers medium plate, a hybrid medium plate of Rogers and FR-4, etc. Here, FR-4 is a code of a flame retardant material grade, and the Rogers medium plate is a high-frequency plate. The side of the printed circuit board PCB 17 close to the middle frame 19 can be provided with a metal layer, which can be formed by etching metal on the surface of the PCB 17. The metal layer can be used for grounding the electronic components carried on the printed circuit board PCB 17 to prevent user electric shock or equipment damage. The metal layer can be referred to as a PCB floor. Without being limited to the PCB floor, the electronic device 10 can also have other floors for grounding, such as a metal middle frame.

[0048] The electronic device 10 can also include a battery (not shown in the figure). The battery can be disposed in the middle frame 19, and the battery can divide the PCB 17 into a main board and a sub-board. The main board can be disposed between the upper edge of the middle frame 19 and the battery, and the sub-board can be disposed between the lower edge of the middle frame 19 and the battery.

[0049] The middle frame 19 mainly plays a supporting role for the whole machine. The middle frame 19 can include the bezel 11, which can be formed of a conductive material such as metal. The bezel 11 can extend around the periphery of the electronic device 10 and the display module 15, and specifically can surround the four sides of the display module 15 to help fix the display module 15. In an implementation, the bezel 11 made of metal material can be directly used as the metal bezel of the electronic device 10 to form the appearance of the metal bezel, which is suitable for metal industrial design (ID). In another implementation, the outer surface of the bezel 11 can also be a non-metal material, such as a plastic bezel, to form the appearance of the non-metal bezel, which is suitable for non-metal ID.

[0050] The back cover 21 can be a back cover made of metal material, or a back cover made of non-conductive material, such as a glass back cover, a plastic back cover, etc.

[0051] Figure 1 Only some components included in the electronic device 10 are schematically shown, and the actual shape, actual size, and actual structure of these components are not limited in the present application. Figure 1limited.

[0052] It should be understood that, in this application, the side of the electronic device where the display screen is located can be considered as the front, the side where the back cover is located as the back, and the side where the frame is located as the side.

[0053] With the development of 5G wireless communication systems, the demand for antennas has increased significantly, requiring antennas to be installed on the back of electronic devices, such as... Figure 2 As shown. Antennas located on the back of electronic devices are typically patch antennas. To avoid affecting the antenna's radiation performance, the back cover of electronic devices has begun to evolve towards non-metallic designs. However, the power consumption of chips corresponding to 5G wireless communication systems will be approximately 2.5 times that of 4G, resulting in a sharp increase in power consumption and heat generation during operation. Since the back cover of electronic devices is non-metallic, heat dissipation is poor, requiring additional heat dissipation designs, such as... Figure 2 As shown, the heat generated in the high-heat area (the area where the chip is located on the PCB) is transferred to the low-heat area (the area where the battery is located) by using graphene film as a heat dissipation component, so that the heat is evenly distributed.

[0054] It should be understood that for patch antennas, achieving high over-the-air (OTA) performance and low specific absorption rate (SAR) typically requires a large area. However, because the graphene film used as a heat sink has a large area, and because the graphene film needs to remain intact to have heat dissipation properties, it essentially occupies most of the space on the back of electronic devices. Therefore, there is a strong conflict between the number of antennas required in electronic devices and the heat dissipation requirements.

[0055] This application provides a method for preparing a graphene film. The graphene film includes regions with different resistance values ​​and can be applied to electronic devices. The whole film can be used as a heat sink for electronic devices, and its low-resistivity regions can be used as antenna radiators. This method can balance the radiation characteristics of the antenna and the heat dissipation performance of the heat sink, effectively resolving the contradiction between the two.

[0056] Figure 3 and Figure 4 This is a schematic diagram of the structure of the electronic device provided in an embodiment of this application. Figure 3 This is a cross-sectional schematic diagram of the electronic device provided in the embodiments of this application. Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application.

[0057] like Figure 3As shown, the electronic device can include a graphene film 110 and a heat generating device 101, and the graphene film 110 can be arranged above the heat generating device 101 to transfer heat generated by the heat generating device 101 when the heat generating device 101 is working, so as to avoid overheating of the heat generating device 101 and affect the working efficiency of the heat generating device 101. The graphene film 110 can include a first region 111 and a second region 112, and the graphene film in the first region 111 has a different conductivity from the graphene film in the second region 112, or the graphene film in the first region 111 has a different resistance value from the graphene film in the second region 112. In the embodiments of the present application, only the case that the graphene film in the first region 111 has a higher conductivity than the graphene film in the second region 112, or the graphene film in the first region 111 has a lower resistance value than the graphene film in the second region 112 is described. The conductivity, also known as the conductance, can be used to describe the difficulty of charge flow in a substance. The conductivity is related to the resistance value. Generally, high conductivity corresponds to low resistance value, and low conductivity corresponds to high resistance value.

[0058] In one embodiment, the heat generating device 101 can be a processing chip in the electronic device, or other types of chips.

[0059] It should be understood that by multiplexing the graphene film 110, the problem of mutual influence between the heat dissipation component and the radiator of the antenna structure in the electronic device is solved. The graphene film 110 provided in the embodiments of the present application can transfer the heat generated by the heat source (heat generating device, such as processor, etc.) to the low heat area (such as the area where the battery is located). Since the graphene film 110 is a complete film, there is no interval between the first region 111 and the second region 112, and the graphene film in the first region 111 and the graphene film in the second region 112 can be regarded as a whole, so that the heat conducted at the heat source can be uniformly distributed on the entire graphene film, so as to achieve the purpose of cooling the overheated electronic element. At the same time, the graphene film 110 in the first region with low resistance value (high conductivity) can be used as the radiator of the antenna structure to generate radiation outward.

[0060] As shown in FIGS. Figure 3 and Figure 4 The electronic device can include a PCB 17, a middle frame 19, a battery 20 and a back cover 21.

[0061] The graphene film 110, the PCB 17 and the battery 20 can be arranged in the space enclosed by the middle frame 19 and the back cover 21. Part of the graphene film 110 can be arranged between the PCB 17 and the back cover 21. In some embodiments, the graphene film 110 can be attached to the back cover.

[0062] In an embodiment, the heat generating device 101 can be disposed on the PCB 17. It should be understood that the heat generating device 101 can also be disposed on a flexible printed circuit (FPC) or a low pin count (LPC) bus, and the present application does not limit this.

[0063] In an embodiment, the electronic device can further include a battery 20, and part of the graphene film 110 can be disposed between the battery 20 and the back cover 21, serving as a low-heat zone. Part of the graphene film 110 can also not be disposed between the battery 20 and the back cover 21, and the placement position of the heat dissipation device can be changed according to the actual layout in the electronic device, and the present application does not limit this.

[0064] In an embodiment, a plurality of first regions 111 can be disposed on the graphene film 110, and the present embodiment takes four first regions 111 as an example, four antenna units can be formed to meet the demand of the number of antennas of the 5G wireless communication system, and can be applied to a multi-input multi-output (MIMO) antenna system, and can also be applied to other communication systems. At the same time, the graphene film of the second region 112 between the four first regions 111 can be used as an insulating material because of its high resistance value (low conductivity), thereby preventing the graphene films of the four first regions 111 from affecting each other when they are used as radiators of the antenna structure.

[0065] In an embodiment, a third region can also be disposed on the graphene film 110, and the resistance value of the graphene film of the third region can be between the resistance value of the graphene film of the first region 111 and the resistance value of the graphene film of the second region 112, and the conductivity of the graphene film of the third region can be between the conductivity of the graphene film of the first region 111 and the conductivity of the graphene film of the second region 112. It should be understood that the present embodiment provides that the graphene film 110 can include a plurality of regions with different resistance values or different conductivities, and the present application does not limit this, which can be adjusted according to actual production or design needs.

[0066] In an embodiment, the resistance value of the graphene film of the first region 111 can be less than or equal to 20Ω, and the graphene film of the first region 111 can be used as a radiator of the antenna structure. The resistance value of the graphene film of the second region 112 can be greater than or equal to 20 times the resistance value of the graphene film of the first region 111, for example, 400Ω. In this case, when the graphene film of the first region 111 is used as a radiator of the antenna structure, the graphene film of the second region 112 can be considered as an insulating material, thereby avoiding affecting the graphene film of the first region 111 as a radiator of the antenna structure.

[0067] In one embodiment, the graphene film of the first region 111 can have an electrical conductivity greater than or equal to 10 4 S / m, the graphene film of the first region 111 can be used as a radiator of an antenna structure. The graphene film of the second region 112 can have an electrical conductivity less than or equal to 10 S / m. In this case, when the graphene film of the first region 111 is used as a radiator of an antenna structure, the graphene film of the second region 112 can be considered as an insulating material, avoiding affecting the graphene film of the first region 111 as a radiator of an antenna structure.

[0068] In one embodiment, the graphene film 110 is provided with an insulating layer close to the electronic device middle frame 19, avoiding the short circuit between the graphene film of the first region 111 and the shielding cover 171 on the battery 20 or the PCB 17.

[0069] In one embodiment, the insulating layer can be an adhesive, such as a heat-conducting gel, for tightly contacting the graphene film 110 with the heat source on the PCB, and conducting heat well.

[0070] In one embodiment, the electronic device can further include a feeding unit, which can be electrically connected with the graphene film of the first region 111, and feed the antenna structure formed by the graphene film of the first region 111. The feeding unit can be a radio frequency channel in a radio frequency chip inside the electronic device.

[0071] In one embodiment, the graphene film of the first region 111 and the graphene film of the second region 112 can have different electrical resistances in various ways. For example, the annealing temperature and the rolling pressure during the preparation of the graphene film of the first region 111 and the graphene film of the second region 112 can be adjusted, or the thickness of the graphene film of the first region 111 and the thickness of the graphene film of the second region 112 can be adjusted, or the graphene film with two different electrical resistances can be bonded by a heat-conducting gel to form the graphene film 110. The present application does not limit the above ways, and there can be various ways to make the graphene film of the first region 111 and the graphene film of the second region 112 have different electrical resistances.

[0072] In the technical scheme provided in the embodiments of the present application, the graphene film with a low electrical resistance (high electrical conductivity) is used to realize antenna radiation, and the graphene film with a low electrical resistance and a high electrical resistance is used to realize heat dissipation. By adding some special processes during the preparation of the graphene film, a graphene film with a complete piece can include regions with different electrical resistances, which can have both high electrical resistance and low electrical resistance. Figure 5A process flow chart for processing a graphene film with a low resistance value. In the process flow for preparing the graphene film, the resistance value of the graphene film is mainly controlled in the annealing and rolling processes. The higher the annealing temperature and the greater the rolling pressure, the lower the resistance value and the higher the conductivity of the graphene film. The lower the annealing temperature and the smaller the rolling pressure, the higher the resistance value and the lower the conductivity of the graphene film. Based on the above technical principle, three methods for preparing graphene films with mixed resistance values are provided in the present application.

[0073] Figure 6 and Figure 7 is a schematic diagram of a method for preparing a graphene film provided by an embodiment of the present application. In the method, Figure 6 is a schematic diagram of a method for preparing a graphene film. Figure 7 is a process flow chart of a method for preparing a graphene film.

[0074] As shown in Figure 6 , the graphene film shown in Figure 3 may include the following steps:

[0075] 1. A graphene oxide suspension with a first concentration is prepared, and the concentration of the graphene oxide suspension can be determined according to the actual design, and the graphene oxide suspension is dried to obtain a graphene oxide film.

[0076] 2. The graphene oxide film is annealed, and the graphene oxide film can include a first region and a second region, the annealing temperature of the graphene oxide film in the first region is different from the annealing temperature of the graphene oxide film in the second region, and a first graphene film is obtained.

[0077] In one embodiment, the annealing temperature can be between 0°C and 2800°C, which can be adjusted according to the specific design, and the present application does not limit this.

[0078] 3. The first graphene film is rolled, and the rolling pressure of the first graphene film in the first region is different from the rolling pressure of the first graphene film in the second region, and a second graphene film is obtained.

[0079] In one embodiment, the rolling pressure can be between 0MPa and 600MPz, which can be adjusted according to the specific design, and the present application does not limit this.

[0080] It should be understood that the second graphene film is the graphene film shown in the above Figure 3 , different annealing temperatures and rolling pressures are loaded in different regions of the graphene material to achieve different impedance values in different regions. For different regions, only the annealing temperature or the rolling pressure is controlled to be different, and the same technical effect can also be achieved.

[0081] As shown in Figure 7As shown in the specific process flow diagram, it should be understood that the process flow diagram provided by the embodiments of the present application is only used as an example, and other processes can also be replaced to achieve the same technical effect.

[0082] As shown in the specific process flow diagram, it should be understood that the process flow diagram provided by the embodiments of the present application is only used as an example, and other processes can also be replaced to achieve the same technical effect. Figure 7 As shown in the specific process flow diagram, it should be understood that the process flow diagram provided by the embodiments of the present application is only used as an example, and other processes can also be replaced to achieve the same technical effect.

[0083] The graphene oxide powder can be diluted to obtain a graphene oxide suspension.

[0084] The graphene powder is uniformly distributed by ultrasonic waves, and impurities are filtered out by suction filtration. The time of ultrasonic treatment and suction filtration can be adjusted according to actual production or design requirements. For example, the time of ultrasonic treatment can be 30 minutes, and the time of suction filtration can be 8 hours.

[0085] The treated graphene solution is dried to obtain a graphene oxide film. The drying temperature can be adjusted according to actual production or design requirements. For example, the drying temperature can be 80°C.

[0086] Different regions of the graphene oxide film are annealed at different temperatures. A reducing agent can be added during annealing. The graphene oxide is reduced to graphene during annealing to obtain a first graphene film.

[0087] Different regions of the first graphene film are rolled at different pressures to obtain a second graphene film.

[0088] It should be understood that the higher the annealing temperature and the greater the rolling pressure, the lower the resistance value and the higher the conductivity of the graphene film. The lower the annealing temperature and the smaller the rolling pressure, the higher the resistance value and the lower the conductivity of the graphene film. Therefore, the resistance value of the first region and the resistance value of the second region can be adjusted by controlling the annealing temperature of the first region and the second region of the graphene oxide film, or by controlling the rolling pressure of the first region and the second region of the first graphene film.

[0089] Since the graphene film is a soft material, the second graphene film can be attached to a polyethylene terephthalate (PET) substrate to obtain a complete second graphene film. An ultraviolet curing paint (UV) primer is sprayed to cure the second graphene film and improve its physical strength.

[0090] The second graphene film can be transferred from the PET substrate to the dielectric substrate to obtain graphene films with different resistance values ​​for subsequent processing, such as adding an insulating layer or encapsulating the graphene film. This application does not limit this.

[0091] Figure 8 This is a schematic diagram of the structure of a graphene film provided in an embodiment of this application.

[0092] Table 1 shows the relationship between the thickness of graphene films and their use as antenna radiators. As can be seen from Table 1, the thicker the graphene film, the higher the antenna gain, the lower the resistance of the graphene film, and the higher its conductivity. Conversely, the thinner the graphene film, the lower the antenna gain, the higher the resistance of the graphene film, and the lower its conductivity.

[0093] Table 1

[0094] H / mm Operating band / GHz S11 min / dB Gain / dBi 0.030 2.40-2.48 -48 2.52 0.020 2.41-2.48 -27 2.33 0.010 2.41-2.48 -22 1.77 0.005 2.41-2.48 -15 0.62 0.003 2.41-2.48 -11 -7.10

[0095] Based on the above basic conclusions, high-impedance (low-conductivity) barriers can be generated around the film serving as the antenna radiator in a complete low-impedance (high-conductivity) graphene film by carving or peeling, thereby realizing the fabrication of mixed-impedance graphene.

[0096] like Figure 8 As shown, in a low-impedance graphene film, the graphene film in the first region 211 can serve as an antenna radiator, reducing the height of the graphene film in the second region 212 to achieve a high-resistance region. When the graphene film in the first region 211 serves as an antenna radiator, the graphene film in the second region 212 can enclose the graphene film in the first region 211. The graphene film in the second region 212 can also serve as a high-resistance insulating material, preventing other low-impedance graphene films from affecting it.

[0097] It should be understood that a graphene film may include multiple first regions 211, meaning that multiple antenna radiators can be disposed in the same graphene film, and this application does not limit this. For example, multiple second regions 212 can be formed on other low-resistivity graphene films by engraving or peeling, thereby enclosing multiple first regions that can serve as other antenna radiators.

[0098] like Figure 9 As shown, preparation Figure 8 The graphene film shown may include the following steps:

[0099] 1. Prepare a graphene film with the first resistance value.

[0100] 2. Forming the first region and the second region on the graphene film by engraving or peeling, wherein the thickness of the graphene film of the first region is greater than the thickness of the graphene film of the second region, that is, the thickness of the graphene film of the second region is reduced by engraving or peeling, thereby increasing the corresponding resistance value of the second region, so that it is greater than the first resistance value, thereby preparing the graphene film including different resistance values.

[0101] As shown in Figure 10 , it is a specific process flow chart, and it should be understood that the process flow chart provided by the embodiments of the present application is only used as an example, and other processes can also be replaced to achieve the same technical effect.

[0102] As shown in Figure 10 , the graphene film including different resistance values can be prepared by the following steps:

[0103] The graphene film with low resistance value (high conductivity) is prepared. Among them, the graphene film with low resistance value can be directly prepared by controlling the annealing temperature and the rolling pressure in the above preparation method, or the graphene film with low resistance value can also be prepared by rolling the graphene film with high resistance value (low conductivity) under a certain pressure, and the present application does not limit this.

[0104] The high resistance value region (the second region in the above embodiment) on the graphene film is determined, and the thickness of the graphene film corresponding to the region needs to be reduced by engraving to improve the resistance value of the graphene film corresponding to the region.

[0105] The graphene film to be processed is cleaned to ensure that the engraving precision is not affected by impurities during engraving, thereby affecting the corresponding resistance value.

[0106] Spray polyurethane (PU) primer to improve the oil resistance, wear resistance, low temperature resistance, aging resistance and other abilities of the graphene film.

[0107] Vacuum coating is performed on the graphene film with low resistance value region, and a carving protection layer is sprayed to avoid the influence of carving on the graphene film with low resistance value region.

[0108] Adjust the temperature of the engraving machine, and also adjust the humidity range of the environment to improve the working precision of the engraving machine and avoid the influence of environmental temperature and humidity.

[0109] Doping the high resistance value (low conductivity) material with adhesion in the engraved region, so that the region still guarantees a certain physical strength after reducing the thickness of the region by engraving.

[0110] The high-resistance value region is engraved by a laser engraving machine, so that the thickness of the graphene film in the high-resistance value region after engraving can be controlled, for example, the thickness range of the graphene film can be 0.002 mm-0.03 mm, and the corresponding resistance value is 500 Ω-0.03 Ω.

[0111] The UV primer is sprayed to solidify the graphene film and improve the physical strength of the graphene film.

[0112] The protective layer is sprayed to obtain the graphene film including graphene films with different resistance values.

[0113] Figure 11 The graphene film including graphene films with different resistance values is prepared by another method provided in the embodiment of the present application.

[0114] As shown in Figure 11 , the graphene film shown in Figure 3 may include the following steps:

[0115] 1. The graphene film with a first resistance value and the graphene film with a second resistance value are prepared, and the first resistance value and the second resistance value are different. The graphene films with different resistance values can be directly prepared by controlling the concentration of the graphene oxide suspension, the annealing temperature or the rolling pressure in the above preparation method.

[0116] It should be understood that the present application does not limit the preparation method of the graphene film with the first resistance value and the graphene film with the second resistance value, and the graphene film with the first resistance value and the graphene film with the second resistance value can also be prepared by other methods, for example, by chemical vapor deposition (CVD), epitaxial growth, mechanical exfoliation, etc., and the present application does not limit this.

[0117] 2. The graphene film with the first resistance value and the graphene film with the second resistance value are cut, and the desired size can be cut according to the design, as shown in Figure 12 .

[0118] 3. The cut graphene film with the first resistance value and the cut graphene film with the second resistance value are bonded by the heat-conducting gel to obtain the graphene film including graphene films with different resistance values. This step can also include rolling the bonded graphene film to make the connection of the cut graphene film with the first resistance value and the cut graphene film with the second resistance value more secure.

[0119] As shown in Figure 13 , it is a specific process flowchart, and it should be understood that the process flowchart provided in the embodiment of the present application is only used as an example, and other processes can also be used to achieve the same technical effect.

[0120] As shown in Figure 13As shown, graphene films with different resistance values can be prepared by the following steps, which are one of the possible ways provided by the present application, and can also be prepared by other ways:

[0121] The graphene oxide powder can be diluted to prepare a graphene oxide suspension.

[0122] The graphene powder is uniformly distributed by ultrasonic waves, and impurities are filtered out by suction filtration. The time of ultrasonic treatment and suction filtration can be adjusted according to actual production or design requirements. For example, the time of ultrasonic treatment can be 30 minutes, and the time of suction filtration can be 8 hours.

[0123] The treated graphene solution is dried to prepare a graphene oxide film. The drying temperature can be adjusted according to actual production or design requirements. For example, the drying temperature can be 80℃.

[0124] The high-temperature atmosphere furnace is pre-filled with nitrogen. The high-temperature atmosphere furnace is used for annealing the graphene oxide film. A reducing agent needs to be added during the annealing process. The graphene oxide is reduced to graphene during the annealing process. Therefore, it is necessary to ensure that the high-temperature atmosphere furnace is filled with inert gas to ensure the reduction process. The time of pre-filling the high-temperature atmosphere furnace with nitrogen can be determined according to the size of the high-temperature atmosphere furnace and other factors. For example, the time of pre-filling the high-temperature atmosphere furnace with nitrogen can be 30 minutes.

[0125] The graphene oxide film is annealed in the high-temperature atmosphere furnace to prepare a graphene film with a first resistance value and a graphene film with a second resistance value. The first resistance value and the second resistance value are different. It should be understood that the resistance values of the graphene films can be adjusted by controlling the concentration of the graphene oxide suspension or the annealing temperature to prepare two graphene films with different resistance values. At the same time, the annealing temperature can be between 0℃ and 2800℃ during the annealing process, and the annealing time can be adjusted according to the specific design. For example, 2 hours. The present application does not limit this. After the annealing is completed, the high-temperature atmosphere furnace can be cooled to 50℃.

[0126] The graphene film with the first resistance value is transferred to the medium substrate (for example, the first resistance value is less than the second resistance value).

[0127] The cutting area with the required second resistance value is cut out.

[0128] The heat-conducting gel is uniformly sprayed so that the connection between the graphene film with the first resistance value and the graphene film with the second resistance value has good heat conduction performance. The prepared graphene film can become a complete heat dissipation piece with good heat conduction performance.

[0129] The graphene film with the second resistance value is cut and covers the cutting area. The graphene film with the second resistance value is cut according to the shape required by the design.

[0130] The graphene film after bonding is rolled to obtain graphene films with different resistance values. The rolling can further improve the stability of the connection between the graphene film with the first resistance value and the graphene film with the second resistance value. The rolling pressure can be between 0 MPa and 600 MPz, for example, 300 MPa, which can be adjusted according to the specific design, and the application does not limit this.

Claims

1. An electronic device, comprising: The electronic device comprises: a graphene film and a heating device; wherein part of the graphene film is arranged above the heating device; the graphene film comprises a first region and a second region, the graphene film in the first region has a different resistance value from the graphene film in the second region, or the graphene film in the first region has a different conductivity from the graphene film in the second region; wherein the graphene film in the first region has a smaller resistance value than the graphene film in the second region, or the graphene film in the first region has a larger conductivity than the graphene film in the second region; part of the graphene film in the first region serves as a radiator of an antenna structure of the electronic device.

2. The electronic device of claim 1, wherein, The thickness of the graphene film in the first region is different from the thickness of the graphene film in the second region.

3. The electronic device of claim 1, wherein, The graphene film in the first region and the graphene film in the second region are bonded by a heat-conducting gel.

4. The electronic device of claim 1, wherein, The electronic device further comprises a printed circuit board (PCB); the heating device is arranged on the PCB.

5. The electronic device of claim 4, wherein, The electronic device further comprises a middle frame, a back cover and a battery; the PCB and the battery are arranged in a space enclosed by the middle frame and the back cover; part of the graphene film is arranged between the PCB and the back cover.

6. The electronic device of claim 5, wherein, The electronic device further comprises a battery; part of the graphene film is arranged between the battery and the back cover.

7. The electronic device of claim 5, wherein, An insulating layer is arranged on one side of the graphene film close to the middle frame.

8. A method of producing a graphene film, characterized by, The method comprises: preparing an oxidized graphene suspension and drying the oxidized graphene suspension to obtain an oxidized graphene film; annealing the oxidized graphene film to obtain a first graphene film; rolling the first graphene film to obtain a second graphene film with different resistance values; wherein the oxidized graphene film comprises a first region and a second region, the annealing temperature of the oxidized graphene film in the first region is different from the annealing temperature of the oxidized graphene film in the second region, or the rolling pressure of the first graphene film in the first region is different from the rolling pressure of the first graphene film in the second region.

9. The production method according to claim 8, characterized by, The rolling pressure is between 0 MPa and 600 MPz.

10. The method of claim 9, wherein, The annealing temperature is between 0℃ and 2800℃.

11. A method of producing a graphene film, characterized by, The method comprises: preparing a graphene film with a first resistance value; forming a first region and a second region on the graphene film by carving or peeling to obtain a graphene film with different resistance values, the thickness of the graphene film in the first region is greater than the thickness of the graphene film in the second region; wherein the graphene film in the first region has a smaller resistance value than the graphene film in the second region, or the graphene film in the first region has a larger conductivity than the graphene film in the second region; part of the graphene film in the first region serves as a radiator of an antenna structure.

12. The method of claim 11, wherein, The method of preparing a graphene film with a first resistance value comprises: preparing an oxidized graphene suspension and drying the oxidized graphene suspension to obtain an oxidized graphene film; annealing and rolling the oxidized graphene film to obtain the graphene film with the first resistance value.

13. The method of claim 12, wherein, The preparation of the graphene film with the first resistance value comprises: The preparation of the graphene film with the second resistance value, which is greater than the first resistance value; The graphene film with the second resistance value is rolled to obtain the graphene film with the first resistance value.

14. A method of producing a graphene film, characterized by, Comprise: The preparation of the graphene film with the first resistance value and the graphene film with the second resistance value, which are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; 15. The preparation method according to claim 14, characterized in that, The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; 16. The method of claim 15, wherein, The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second resistance value are different; The first resistance value and the second

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