CN115666109A

CN115666109A - Heat-conducting film, preparation method, electronic component, circuit board assembly and electronic equipment

Info

Publication number: CN115666109A
Application number: CN202211498535.7A
Authority: CN
Inventors: 郑钦文; 杨帆; 雷高兵
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2022-11-28
Filing date: 2022-11-28
Publication date: 2023-01-31

Abstract

The application provides a heat-conducting film, a preparation method of the heat-conducting film, an electronic component, a circuit board assembly and electronic equipment, relates to the technical field of heat dissipation of electronic equipment, and is used for solving the problem of how to improve the heat dissipation efficiency of a high-integration-level chip. The heat conducting film comprises a vertical graphene film, the vertical graphene film extends along a first direction, and in a plane perpendicular to the first direction, the vertical graphene film extends along a spiral line. The heat conduction membrane that this application embodiment provided is used for following first direction heat conduction.

Description

Heat-conducting film, preparation method, electronic component, circuit board assembly and electronic equipment

Technical Field

The application relates to the technical field of heat dissipation of electronic equipment, in particular to a heat-conducting film, a preparation method of the heat-conducting film, an electronic component, a circuit board assembly and electronic equipment.

Background

At present, electronic components on a circuit board in electronic equipment such as a mobile phone and a tablet computer are gradually developed towards a high integration degree. For example, the number of integrated circuit transistors has undergone integration from small scale to ultra large scale, from two-dimensional to three-dimensional stereo space. To date, billions of transistors can be integrated in a nail-sized chip. This trend of high integration has dramatically increased the heat flux density of the chip system.

High heat flux density and high integration of the system pose serious challenges to thermal management. The operating speed of the transistor decreases by 1 time for every 15 ℃ increase in temperature. In the current 5G chip power consumption era, i.e., in the environment of higher density integration and higher frequency computing, attention should be paid to solving the problem of heat dissipation of the chip, and solving the problem of heat generation of the chip has become a significant challenge in the development of moore's law.

Disclosure of Invention

The embodiment of the application provides a heat-conducting film, a preparation method of the heat-conducting film, an electronic component, a circuit board assembly and electronic equipment, and is used for solving the problem of how to improve the heat dissipation efficiency of an integrated chip.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, a thermally conductive film is provided that includes a vertical graphene film extending in a first direction, and the vertical graphene film extends along a spiral line in a plane perpendicular to the first direction.

When being applied to this heat conduction membrane between heat source (for example chip) and the heat radiation structure (for example heat dissipation frame) in the electronic equipment, in the heat conduction membrane, graphite alkene sets up upright, and the graphite alkene coefficient of heat conductivity of setting upright is higher, can promote by heat source to heat radiation structure's heat conduction efficiency, is favorable to promoting the radiating efficiency of heat source. Meanwhile, in a plane perpendicular to the first direction, the vertical graphene film extends along a planar spiral line, so that the vertical graphene film can be obtained by slicing the wound graphene film, the processing difficulty of the vertical graphene film is reduced, and the microscopic direction of the graphene can be effectively controlled.

In one possible implementation manner of the first aspect, the heat conducting film further includes a heat conducting paste and/or a heat conducting liquid. The heat conducting paste and/or the heat conducting liquid are/is arranged on at least one end face of the vertical graphene film along the first direction. Therefore, when the heat conduction film is applied between a heat source and a heat dissipation structure in an electronic device, the heat conduction paste and/or the heat conduction liquid is/are located between one end, facing the heat source, of the vertical graphene film and the heat source, and/or the heat conduction paste and/or the heat conduction liquid is located between one end, facing the heat dissipation structure, of the vertical graphene film and the heat dissipation structure, so that the contact thermal resistance between one end, facing the heat source, of the vertical graphene film and the heat source and/or between one end, facing the heat dissipation structure, of the vertical graphene film and the heat dissipation structure can be reduced, and the heat conduction efficiency is improved.

In one possible implementation manner of the first aspect, the thermal conductive paste and/or the thermal conductive liquid is further disposed between two adjacent inner and outer portions of the vertical graphene film in a plane perpendicular to the first direction. Therefore, the heat conduction efficiency between the inner part and the outer part of the vertical graphene film extending along the spiral line can be improved, so that the soaking effect is achieved, and the heat conduction efficiency from the heat source to the heat dissipation structure can be improved.

In one possible implementation manner of the first aspect, the heat conducting paste is heat conducting gel or heat conducting silicone grease, and the heat conducting liquid is lubricating oil, heat conducting oil or liquid metal containing at least one component of gallium, indium, tin, zinc and silver.

In a possible implementation manner of the first aspect, the heat conduction film further includes an encapsulation film, the encapsulation film includes a first encapsulation film portion and a second encapsulation film portion, and the first encapsulation film portion, the upright graphene film, and the second encapsulation film portion are sequentially arranged along a first direction; the heat-conducting paste and/or the heat-conducting liquid are/is located between the first packaging film part and the second packaging film part. In a plane perpendicular to the first direction, an edge of the first encapsulating film portion is located outside a projection of the erected graphene film on the first encapsulating film portion, and an edge of the second encapsulating film portion is located outside a projection of the erected graphene film on the second encapsulating film portion. The edge of the first packaging film part is connected with the edge of the second packaging film part in a circle. In this way, the heat conductive paste and/or the heat conductive liquid can be encapsulated by the encapsulation film, and leakage of the heat conductive paste and/or the heat conductive liquid can be avoided.

In one possible implementation of the first aspect, the graphene film includes a plurality of graphene film layers stacked one on another. The thickness of the plurality of vertical graphene film layers is large, and the spiral winding efficiency is excellent.

In a second aspect, an electronic component is provided, which includes a substrate, a chip, a heat dissipation frame, and a heat conductive film. The substrate has a first surface. The chip is arranged on the first surface. The heat dissipation frame comprises a heat dissipation plate, and the heat dissipation plate is located on one side, far away from the substrate, of the chip. The heat conducting film is the heat conducting film according to any one of the technical solutions of the first aspect, the heat conducting film is disposed between the chip and the heat dissipation plate, and the first direction of the graphene film standing vertically in the heat conducting film is directed to the heat dissipation plate from the chip.

Therefore, in the heat conduction membrane, the graphene is vertically arranged, the heat conduction coefficient of the vertically arranged graphene is higher, the heat conduction efficiency from the chip to the heat dissipation frame can be improved, and the heat dissipation efficiency of the chip is favorably improved.

In a third aspect, a circuit board assembly is provided that includes a circuit board, an electronic component, a shield can, and a thermally conductive film. The circuit board has a second surface. The electronic component is arranged on the second surface. The shielding case comprises a shielding plate, and the shielding plate is positioned on one side of the electronic component far away from the circuit board. The heat conduction membrane is any technical scheme of the first aspect, the heat conduction membrane is arranged between the electronic component and the shielding plate, and the first direction of the graphene membrane standing vertically in the heat conduction membrane is pointed to the shielding plate by the electronic component.

Therefore, in the heat conduction membrane, the graphene is vertically arranged, the vertically arranged graphene heat conduction coefficient is higher, the heat conduction efficiency from the electronic component to the shielding plate can be improved, and the heat dissipation efficiency of the electronic component is favorably improved.

In a fourth aspect, an electronic device is provided that includes a circuit board assembly, a chassis, and a thermally conductive film. The circuit board assembly comprises a circuit board, an electronic component, a shielding case and a thermal interface material. The circuit board has a second surface. The electronic component is arranged on the second surface. The shielding case comprises a shielding plate, and the shielding plate is positioned on one side of the electronic component far away from the circuit board. The thermal interface material is disposed between the electronic component and the shielding plate. The chassis is located on a side of the shield plate away from the circuit board. The heat conducting film is the heat conducting film according to any one of the technical solutions of the first aspect, the heat conducting film is disposed between the shielding plate and the case, and the first direction of the graphene film standing in the heat conducting film is directed to the case from the shielding plate.

Thus, in the heat conduction membrane, the graphene is vertically arranged, the vertically arranged graphene heat conductivity coefficient is higher, the heat conduction efficiency from the shielding plate to the shell can be improved, and the heat dissipation efficiency of the circuit board assembly is favorably improved.

In a fifth aspect, an electronic apparatus is provided that includes a circuit board, an electronic component, a heat sink, and a heat conductive film. The circuit board has a third surface. The electronic component is arranged on the third surface. The radiator is positioned on one side of the electronic component far away from the circuit board. The heat conduction membrane is the heat conduction membrane described in any technical scheme of the first aspect, the heat conduction membrane is arranged between the electronic component and the radiator, and the electronic component points to the radiator in the first direction of the graphene membrane standing vertically in the heat conduction membrane.

Therefore, in the heat conduction membrane, the graphene is vertically arranged, the heat conduction coefficient of the vertically arranged graphene is higher, the heat conduction efficiency from the electronic component to the radiator can be improved, and the heat dissipation efficiency of the electronic component can be improved.

In a sixth aspect, a method for producing a thermally conductive film is provided, the method comprising:

providing a first material membrane; the first material membrane is made of graphene, graphene oxide or a mixture of graphene and graphene oxide;

winding the first sheet of material to form a pillar; wherein the height direction of the upright posts is parallel to the winding axis of the first material membrane;

the pillars are sliced along a cutting plane to obtain a first material film. Wherein, the tangent plane is perpendicular with the direction of height of stand.

The method changes the 0-degree arranged graphene film into 90-degree arranged graphene film, can ensure the vertical effect of the graphene film, improves the heat conduction efficiency, has simple process and low cost, can be scaled and standardized, and is suitable for commercial production.

In a possible implementation manner of the sixth aspect, the material of the first material membrane is graphene oxide, or a mixture of graphene oxide and graphene. After obtaining the first material film, the preparation method further includes: and carrying out reduction treatment on the first material film to obtain a second material film, wherein the second material film is an upright graphene film. The mechanical strength of the graphene oxide or the mixture of the graphene oxide and the graphene is excellent, the winding operation is convenient, the graphene oxide or the mixture of the graphene oxide and the graphene is subjected to reduction reaction to obtain the graphene, the heat conducting performance of the graphene is excellent, and the heat conducting efficiency can be guaranteed.

In a possible implementation manner of the sixth aspect, after obtaining the vertical graphene film, the preparation method further includes: the thermal conductive paste and/or the thermal conductive liquid is provided at least at one end in the extending direction of the winding axis of the vertical graphene film. Therefore, the thermal contact resistance can be reduced by the heat conducting paste and/or the heat conducting liquid, and the heat conducting efficiency is improved.

In a possible implementation manner of the sixth aspect, the first material film includes a plurality of first material layers arranged in a stacked manner, and a material of the first material layers is graphene, graphene oxide, or a mixture of graphene and graphene oxide. Therefore, the thickness of the first material membrane is relatively large, the number of winding layers is small on the premise that the upright columns with the same cross-sectional dimension are formed by winding in the subsequent winding process, and the winding efficiency is high.

Drawings

Fig. 1 is a perspective view of an electronic device provided by some embodiments of the present application;

FIG. 2 is an exploded view of the electronic device shown in FIG. 1;

FIG. 3 is a cross-sectional view of one of the electronic components within the electronic device of FIG. 2;

fig. 4 is a schematic cross-sectional structure diagram of an electronic component according to still further embodiments of the present application;

fig. 5 is a schematic structural view of a heat conductive film in the electronic component shown in fig. 4;

FIG. 6 is a top view of the thermal membrane of FIG. 5;

FIG. 7 is a further top view of the thermal membrane of FIG. 5;

FIG. 8 is yet another top view of the thermal membrane of FIG. 5;

FIG. 9 is yet another top view of the thermal membrane of FIG. 5;

FIG. 10 is an enlarged view of a portion of the thermally conductive membrane of FIG. 5 at area I;

FIG. 11 is an enlarged view of a layer of upstanding graphene film within the thermally conductive film of FIG. 10;

fig. 12 is a schematic view showing a microstructure of a surface of a chip and a surface of a heat dissipation plate in the electronic component shown in fig. 4;

FIG. 13 is a schematic diagram illustrating relative positions of a chip and a heat sink of the electronic component shown in FIG. 12 and the heat conductive film shown in FIG. 5;

FIG. 14 is a schematic structural view of a thermally conductive film according to further embodiments of the present application;

FIG. 15 is a schematic structural view of a thermally conductive film according to still other embodiments of the present application;

FIG. 16 is a schematic structural view of a thermally conductive film according to still other embodiments of the present application;

FIG. 17 is a schematic structural view in the XY-plane of a thermally conductive film according to further embodiments of the present application;

fig. 18 is a cross-sectional structural schematic diagram of a circuit board assembly provided in accordance with some embodiments of the present application;

FIG. 19 isbase:Sub>A cross-sectional view of the electronic device of FIG. 1 along direction A-A;

FIG. 20 is a cross-sectional view of an electronic device provided in accordance with further embodiments of the present application;

FIG. 21 is a flow chart of a method of making a thermally conductive film according to some embodiments of the present application;

FIG. 22 is a schematic structural diagram of a thermal conductivity testing system provided herein;

FIG. 23 is a graph of temperature values measured with a temperature sensor (which may be a contact thermocouple) at a center point of a surface of the heat source facing away from the thermal interface structure in the test system of FIG. 22 as a function of power density of the heat source;

fig. 24 is a schematic structural view of a planar graphene film provided herein;

fig. 25 is a schematic structural diagram of a vertical graphene film provided herein.

Detailed Description

In the embodiments of the present application, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

In the embodiments of the present application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising a … …" does not exclude the presence of another identical element in a process, method, article, or apparatus that comprises the element.

In the embodiment of the present application, "and/or" is only one kind of association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

The present application provides an electronic device including, but not limited to, a mobile phone, a tablet personal computer (tablet personal computer), a notebook computer, a laptop computer (laptop computer), a Personal Digital Assistant (PDA), a personal computer, a smart television, a vehicle-mounted device, a wearable device, a walkman, a radio, and the like. Wherein, wearable device includes but not limited to intelligent bracelet, intelligent wrist-watch, intelligent head-mounted display, intelligent glasses etc..

Referring to fig. 1, fig. 1 is a perspective view of an electronic device 100 according to some embodiments of the present disclosure. The embodiment is exemplified by the electronic device 100 being a tablet phone. The electronic apparatus 100 has an approximately rectangular plate shape. On this basis, for convenience of description of the embodiments to be described later, an XYZ coordinate system is established, and the width direction of the electronic apparatus 100 is defined as the X-axis direction, the length direction of the electronic apparatus 100 is defined as the Y-axis direction, and the thickness direction of the electronic apparatus 100 is defined as the Z-axis direction. It is understood that the coordinate system setting of the electronic device 100 can be flexibly set according to actual needs, and is not particularly limited herein. In other embodiments, the shape of the electronic device 100 may also be a square flat plate, a circular flat plate, an oval flat plate, and the like, which is not limited herein.

Referring to fig. 1 and fig. 2 together, fig. 2 is an exploded schematic view of the electronic device 100 shown in fig. 1. In the present embodiment, the electronic device 100 includes a screen 10, a back case 20, a circuit board 30, an electronic component 40, and a shield case 50.

It is to be understood that fig. 1 and 2 only schematically illustrate some components included in the electronic device 100, and the actual shape, actual size, actual position, and actual configuration of these components are not limited by fig. 1 and 2. In other examples, the electronic device 100 may not include the screen 10.

The screen 10 is used to display images, videos, and the like. The screen 10 includes a light-transmissive cover 11 and a display screen 12 (english name: panel, also called display panel). The light-transmitting cover plate 11 is stacked with the display screen 12. The transparent cover plate 11 is mainly used for protecting the display screen 12 and preventing dust. The material of the transparent cover plate 11 includes, but is not limited to, glass. The display 12 may be a flexible display or a rigid display. For example, the display 12 may be an organic light-emitting diode (OLED) display, an active matrix organic light-emitting diode (AMOLED) display, a mini-OLED (mini-organic light-emitting diode) display, a micro-led (micro-organic light-emitting diode) display, a micro-OLED (micro-organic light-emitting diode) display, a quantum dot light-emitting diode (QLED) display, or a Liquid Crystal Display (LCD). In other embodiments, the screen 10 may not include the light transmissive cover 11.

The back case 20 forms a part of a chassis of the electronic apparatus for protecting internal electronics of the electronic apparatus 100. The back case 20 may include a back cover 21 and a bezel 22. The back cover 21 is located on one side of the display 12 away from the transparent cover plate 11, and is stacked and spaced apart from the transparent cover plate 11 and the display 12. The frame 22 is located between the back cover 21 and the light-transmissive cover plate 11. The frame 22 is fixed on the back cover 21, for example, the frame 22 may be fixedly connected to the back cover 21 by glue, and the frame 22 may also be integrated with the back cover 21, that is, the frame 22 and the back cover 21 are an integral structural component. The light-transmitting cover plate 11 may be fixed to the frame 22 by gluing. The light-transmitting cover plate 11, the back cover 21 and the frame 22 enclose an inner accommodating space of the electronic device 100. The internal receiving space receives the display screen 12, the circuit board 30, the electronic components 40, and the shield case 50 therein.

In some embodiments, referring to fig. 2, the back shell 20 may further include a middle plate 23. The middle plate 23 is disposed in the inner accommodating space, and the middle plate 23 is located on a side of the display 12 away from the transparent cover plate 11. The edge of the middle plate 23 is fixed to the rim 22. In some embodiments, the edge of the middle plate 23 is fixed on the frame 22 by glue, and the middle plate 23 may also be formed integrally with the frame 22, that is, the middle plate 23 and the frame 22 are a structural member. The middle plate 23 divides the inner receiving space into two spaces independent of each other. One of the spaces is located between the light-transmissive cover plate 11 and the middle plate 23, and the display screen 12 is located in this part of the space. Another space is located between the middle plate 23 and the back cover 21, and the circuit board 30 and the electronic component 40 are accommodated in this part of the space. The whole of the middle plate 23 and the frame 22 is also referred to as a middle frame. Midplane 23 forms another portion of the chassis of electronic device 100. In other embodiments, the back shell 20 may not include the middle plate 23.

The circuit board 30 is used to arrange electronic components and to electrically connect a plurality of electronic components. The circuit board 30 may be a hard circuit board, a flexible circuit board, or a rigid-flexible circuit board. The circuit board 30 may be implemented with FR-4 dielectric boards, also with Rogers (Rogers) dielectric boards, also with hybrid FR-4 and Rogers dielectric boards, etc. Here, FR-4 is a code for a grade of flame-resistant material, and the Rogers dielectric plate is a high-frequency plate.

The electronic component 40 is disposed on the circuit board 30. The electronic component 40 is a chip package structure. The electronic component 40 includes, but is not limited to, a system-on-a-chip (SOC), an Application Processor (AP), a Double Data Rate (DDR), a universal flash memory (UFS), a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a CPU mos, a GPU die, a CPU power inductor, a GPU power inductor, or a video access memory (VRAM), and the like, which are not limited in this application.

Referring to fig. 3, fig. 3 is a cross-sectional view of an electronic component 40 in the electronic device 100 shown in fig. 2. The electronic component 40 shown in this embodiment is packaged in a metal Lid (Lid) package. Specifically, the electronic component 40 includes a substrate 41, a chip 42, a heat dissipation frame 43, a Thermal Interface Material (TIM) 44, and a pin terminal 45.

The substrate 41 has a first surface a. The chip 42 is disposed on the first surface a, and the pin terminals 45 are disposed on a surface of the substrate 41 opposite to the first surface a. The pin terminals 45 are used for connection with the circuit board 30 described above. The pin terminals 45 include, but are not limited to, ball Grid Array (BGA) pin terminals. The substrate 41 is used to carry the chip 42 and to realize electrical connection between the chip 42 and the pin terminals 45. Specifically, the substrate 41 may be provided with a metalized via inside, and the surface may be provided with a conductive connection structure such as a pad to electrically connect the chip 42 and the pin terminal 45 together.

The chip 42 is a core device within the electronic component 40. The chip 42 is also called a microcircuit (microcircuit), a microchip (microchip), and an Integrated Circuit (IC). The silicon chip containing the integrated circuit has small volume. With the increase of the integration level of the chip, the chip also has stronger processing capability. But correspondingly, the power consumption of the chip is also increased. It should be understood that chips with greater power consumption also generate more heat during operation, which needs to be dissipated in a timely manner.

In addition, the heat dissipating frame 43 has a metal cover structure. The material of the heat dissipating frame 43 includes, but is not limited to, copper alloy, aluminum alloy, magnesium aluminum alloy, titanium alloy, and the like. The heat dissipation frame 43 is used for dissipating heat of the chip 42 to an external environment of the electronic component 40, and the heat dissipation frame 43 also plays a role in electromagnetic shielding for the chip 42, so as to prevent the chip 42 from generating electromagnetic interference with other surrounding electronic components.

The heat dissipation frame 43 includes a heat dissipation plate 43a and a side frame 43b. The heat dissipation plate 43a is located on a side of the chip 42 away from the substrate 41, and the side frame 43b surrounds the chip 42 and is connected to the heat dissipation plate 43a.

In some embodiments, the heat dissipation plate 43a may be a whole structural member or may be formed by assembling a plurality of parts. The side frame 43b may be formed integrally as a single structural member or may be formed by assembling a plurality of parts. The side frame 43b and the heat dissipating plate 43a may be connected by welding, bonding, or the like, and the side frame 43b and the heat dissipating plate 43a may also be integrally formed, that is, the side frame 43b and the heat dissipating plate 43a are an integral structural component, which is not limited herein.

The thermal interface material 44 is disposed between the chip 42 and the heat dissipation plate 43a, and is in contact with both a surface of the chip 42 facing the heat dissipation plate 43a and a surface of the heat dissipation plate 43a facing the chip 42, and the thermal interface material 44 is used for conducting heat of the chip 42 to the heat dissipation frame 43, so as to further dissipate the heat to the external environment of the electronic component 40 through the heat dissipation frame 43.

At present, the thermal interface material 44 mainly comprises heat-conducting silicone grease, heat-conducting silicone adhesive and liquid metal (liquid gold), the heat conductivity is generally below 10W/(mK), the self thermal resistance of the material is large, and the requirement of heat dissipation of a high-integration/high-heat-power integrated circuit is difficult to meet. The liquid-metal phase has higher thermal conductivity than thermal interface materials such as heat-conducting silicone grease, for example, various gallium-based alloys which are liquid at room temperature have a thermal conductivity of about 30W/(mK), which is obviously improved compared with silicone grease-based liquid-state thermal interface materials, but an internal fence block is usually required to be arranged on a chip of the material to prevent liquid Jin Xielou. In general, the thermal conductivity of the three thermal interface materials, i.e., thermal grease, thermal silicone adhesive, and liquid gold, is not high, and thus the heat dissipation requirement of the future high-integration chip 42 cannot be met.

In order to improve the heat dissipation efficiency of the chip 42, the thermal interface material 44 may be replaced by graphene. Graphene has excellent thermal conductivity and is considered to be a revolutionary material in the future. The heat conduction mechanism of graphene is different from that of a metal material, metal mainly conducts heat by electrons, graphene mainly conducts heat by phonons, and the graphene has ultrahigh heat conduction capability, and the in-layer heat conduction coefficient of graphene is as high as 5300W/(mK), so that a graphene film (or an artificial graphite film) is widely used as a heat conduction film. However, graphene films have limited interlayer thermal conductivity, and only 10W/(mK) -15W/(mK) is difficult to exhibit its thermal conductivity advantage, and thus graphene films cannot be directly used as excellent thermal interface materials.

In order to take advantage of the excellent thermal conductivity properties of graphene, graphene can be fabricated into a vertical structure to enhance the through-plane thermal conductivity. Ideally, the through-plane thermal conductivity of the vertical graphene is comparable to the conventional horizontal thermal conductivity. However, the following problems still remain to be solved when the vertical graphene is used for chip heat dissipation, that is to say: how to control the microscopic direction of the graphene.

To solve the above problem, please refer to fig. 4, where fig. 4 is a schematic cross-sectional structure diagram of an electronic component 40 according to some embodiments of the present application. The electronic component 40 shown in the present embodiment differs from the electronic component 40 shown in fig. 3 in that: in this embodiment, a heat conductive film 46 is disposed between the chip 42 and the heat dissipation plate 43a, and the chip 42 transfers heat to the heat dissipation frame 43 through the heat conductive film 46.

Referring to fig. 5, fig. 5 is a schematic structural diagram of the thermal conductive film 46 in the electronic component 40 shown in fig. 4. In this embodiment. The thermally conductive film 46 includes a standing graphene film 461, the standing graphene film 461 extending in a first direction. The first direction is parallel to the Z-axis direction. When the heat conductive film 46 is applied to the electronic component 40, the first direction is directed from the chip 42 to the heat dissipation plate 43a.

Referring to fig. 6, fig. 6 is a top view of the thermal membrane 46 shown in fig. 5. In a plane perpendicular to the first direction (i.e., the XY plane), the standing graphene film 461 extends along a spiral line. Specifically, in a plane perpendicular to the first direction, the spirally extending path of the graphene film 461 may be a circular spiral.

In another embodiment, referring to fig. 7, fig. 7 is another top view of the thermal membrane 46 shown in fig. 5. In this embodiment, the spiral extending path of the vertical graphene film 461 in the plane perpendicular to the first direction may also be a square spiral.

In another embodiment, referring to fig. 8, fig. 8 is another top view of the thermal membrane 46 shown in fig. 5. In this embodiment, in a plane perpendicular to the first direction, the spiral extending path of the vertical graphene film 461 may also be a triangular spiral.

In another embodiment, referring to fig. 9, fig. 9 is another top view of the thermal membrane 46 shown in fig. 5. In this embodiment, the spiral extending path of the vertical graphene film 461 in the plane perpendicular to the first direction may also be a polygonal spiral line.

Of course, the spiral extending path of the vertical graphene film 461 may also have other shapes, which is not specifically limited in this application, and may be specifically selected according to the shape of the chip 42, so that the shape of the vertical graphene film 461 is adapted to the shape of the chip 42.

Thus, in the heat conduction membrane 46, the graphene is vertically arranged, the heat conductivity coefficient of the vertically arranged graphene is higher, and when the heat conduction membrane is applied to the electronic component 40, the heat conduction efficiency from the chip 42 to the heat dissipation plate 43a can be improved, so that the heat dissipation efficiency of the chip 42 is favorably improved. Meanwhile, in the plane perpendicular to the first direction, the vertical graphene film 461 extends along a planar spiral line, so that the vertical graphene film 461 can be obtained by slicing a graphene film after being wound, which is beneficial to reducing the processing difficulty of the vertical graphene film 461 and effectively controlling the microscopic direction of graphene.

In the above-described embodiment, the upright graphene film 461 may include one upright graphene film layer or a plurality of upright graphene film layers.

Referring to fig. 10, fig. 10 is a partially enlarged view of the thermal conductive film 46 shown in fig. 5 at the area I. In this embodiment, the upright graphene film 461 includes a plurality of upright graphene film layers 4611, and the plurality of upright graphene film layers 4611 are stacked.

Wherein "a plurality" means two or more in number. Specifically, the number of the upright graphene film layers 4611 may be two, three, four, five, and the like, and is not particularly limited herein.

In the embodiment shown in fig. 10, the upright graphene film 461 comprises four upright graphene film layers 4611, the four upright graphene film layers 4611 being disposed in a stack.

When a plurality of upright graphene film layers 4611 are included, the thickness of the upright graphene film 461 is greater and the efficiency of spiral winding is superior compared to an embodiment including one upright graphene film layer 4611.

On the basis of the above embodiments, for convenience of description of the following embodiments, it is defined that a side of each portion of the vertical graphene film 461, which is closer to the spiral axis of the vertical graphene film 461, is an inner side, and a side of each portion of the vertical graphene film 461, which is farther from the spiral axis of the vertical graphene film 461, is an outer side.

On the basis of the above definition, a gap between the inside and outside adjacent two-part upright graphene films 461 in the upright graphene film 461 is defined as a first gap, where the "inside and outside adjacent two-part upright graphene film 461" means: two portions of the upright graphene film 461, which are adjacent in a direction pointing from the inside to the outside, are stacked, and when the upright graphene film 461 is flattened, the two portions are located in different regions on the upright graphene film 461. On this basis, the gap between two adjacent upright graphene film layers 4611 within the upright graphene film 461 is also defined as a second gap. The first gap and the second gap may or may not be equal. When the first gap and the second gap are not equal, the first gap may be larger than the second gap or smaller than the second gap, which is not limited herein.

Since graphene (graphene) is a material in which sp hybridized connected carbon atoms are tightly packed into a single-layer two-dimensional structure, each vertical graphene film layer 4611 includes a plurality of two-dimensional structures stacked in layers, as shown in fig. 11, and fig. 11 is an enlarged view of the vertical graphene film layer 4611 in the thermal conductive film 46 shown in fig. 10, where a plane of the two-dimensional structures is the same as a plane of the vertical graphene film layer 4611, that is, the plurality of two-dimensional structures also extend along the first direction (i.e., the Z-axis direction). So that the graphene stands upright. On the basis, the in-plane thermal conductivity of the graphene along the internal two-dimensional structure is as high as 5300W/(mK), while the thermal conductivity in the lamination direction of the two-dimensional structure is only 10W/(mK) -15W/(mK). Therefore, the heat conductivity in the first direction can be improved, the heat transfer efficiency from the chip 42 to the heat dissipation plate 43a can be improved, and the heat dissipation efficiency of the chip 42 can be improved.

Referring to fig. 12, fig. 12 is a schematic view showing a microstructure of a surface of the chip 42 and a surface of the heat dissipation plate 43a in the electronic component 40 shown in fig. 4. The surface of the chip 42 and the surface of the heat dissipation plate 43a are microscopically uneven. Thus, when the thermal conductive film 46 shown in fig. 5 is applied between the chip 42 and the heat dissipation plate 43a, please refer to fig. 13, and fig. 13 is a schematic diagram of relative positions of the chip 42, the heat dissipation plate 43a and the thermal conductive film 46 shown in fig. 5 in the electronic component 40 shown in fig. 12. The effective contact area between the chip 42 and the thermal conductive film 46 and the effective contact area between the heat dissipation plate 43a and the thermal conductive film 46 are small, and therefore, there is a large thermal contact resistance, and the thermal conductive efficiency of the thermal conductive film 46 in the first direction is still low.

To solve the above problem, in some embodiments, please refer to fig. 14, and fig. 14 is a schematic structural diagram of a thermal conductive film 46 according to still other embodiments of the present application. In the present embodiment, the thermal conductive film 46 includes a thermal conductive paste 462 in addition to the upright graphene film 461. The thermal paste 462 includes, but is not limited to, a thermal gel and a thermal silicone grease. The thermal paste 462 is disposed on at least one end surface of the vertical graphene film 461 in the first direction (i.e., the Z-axis direction). In the embodiment shown in fig. 14, the thermal paste 462 is disposed on both end faces of the vertical graphene film 461 in the first direction.

Thus, when the thermal conductive film 46 is applied to the electronic component 40 shown in fig. 4, the thermal conductive paste 462 may be located between the end of the upright graphene film 461 facing the chip 42 and the chip 42, and the thermal conductive paste 462 may be in contact with both the upright graphene film 461 and the chip 42. Meanwhile, the thermal paste 462 is also disposed between the end of the vertical graphene film 461 facing the heat dissipation plate 43a and the heat dissipation plate 43a, and the thermal paste 462 is in contact with both the vertical graphene film 461 and the heat dissipation plate 43a. Thus, the thermal contact resistances between the vertical graphene film 461 and the chip 42 and between the vertical graphene film 461 and the heat dissipation plate 43a can be reduced by the thermal conductive paste 462, and the thermal conductive efficiency of the thermal conductive film 46 in the first direction (i.e., the Z-axis direction) can be improved.

On the basis of the above-described embodiment, the thermal paste 462 is also disposed between the inside and outside adjacent two portions of the erected graphene film 461 within the erected graphene film 461 in a plane perpendicular to the first direction (i.e., XY plane).

Thus, the heat conduction efficiency between the inner and outer adjacent portions of the vertical graphene film 461 extending along the spiral line can be improved to achieve the heat soaking effect, and the heat conduction efficiency from the chip 42 to the heat dissipation plate 43a can also be improved.

On the basis of the above embodiment, the thermal paste 462 may be disposed between two adjacent upright graphene film layers 4611 in the upright graphene film 461, in addition to between two adjacent inner and outer upright graphene films 461 in the upright graphene film 461. Thus, the heat conduction efficiency between two adjacent vertical graphene film layers 4611 in the vertical graphene film 461 can be improved to achieve the effect of uniform heating, and the heat conduction efficiency from the chip 42 to the heat dissipation plate 43a can also be improved.

Referring to fig. 15, fig. 15 is a schematic structural view of a thermal conductive film 46 according to still other embodiments of the present application. In the present embodiment, the thermal conductive film 46 includes a thermal conductive liquid 463 in addition to the upright graphene film 461. The heat transfer fluid 463 includes, but is not limited to, lubricating oil, heat transfer oil, and other liquid fluids having a heat transfer function, and liquid metals containing at least one component selected from gallium, indium, tin, zinc, and silver. In the embodiment shown in fig. 15, the heat transfer fluid 463 is a gallium-based alloy liquid metal. The thermal conductive liquid 463 is disposed on at least one end surface of the vertical graphene film 461 in the first direction. In the embodiment shown in fig. 15, the thermal conductive liquid 463 is disposed on both end faces of the vertical graphene film 461 in the first direction.

Thus, when the thermal conductive film 46 is applied to the electronic component 40 shown in fig. 4, the thermal conductive liquid 463 may be located between the end of the upright graphene film 461 facing the chip 42 and the chip 42, and the thermal conductive liquid 463 may be in contact with both the upright graphene film 461 and the chip 42. On this basis, the chip 42 may be provided with a groove in which the heat conductive liquid 463 is accommodated and contacts with the bottom wall of the groove, or an annular rib may be provided around the heat conductive liquid 463 on the chip 42, so that the heat conductive liquid 463 is stopped by the side wall of the groove or the annular rib, and the heat conductive liquid 463 is prevented from leaking. Alternatively, the chip 42 is provided with an annular groove around a region in contact with the thermal conductive liquid 463, thereby preventing the thermal conductive liquid 463 from leaking by increasing the contact angle of the thermal conductive liquid 463.

Meanwhile, the heat conductive liquid 463 may be located between the end of the vertical graphene film 461 facing the heat dissipation plate 43a and the heat dissipation plate 43a, and the heat conductive liquid 463 may be in contact with both the vertical graphene film 461 and the heat dissipation plate 43a. Accordingly, the heat dissipating plate 43a may have a groove, and the heat conductive liquid 463 is accommodated in the groove and contacts with the bottom wall of the groove, or an annular rib may be provided on the heat dissipating plate 43a around the heat conductive liquid 463, so that the heat conductive liquid 463 is stopped by the side wall of the groove or the annular rib, and the heat conductive liquid 463 is prevented from leaking. Alternatively, the heat dissipation plate 43a is provided with an annular groove around a region in contact with the thermal conductive liquid 463, thereby preventing the thermal conductive liquid 463 from leaking by increasing the contact angle of the thermal conductive liquid 463.

Therefore, the thermal contact resistances between the vertical graphene film 461 and the chip 42 and between the vertical graphene film 461 and the heat dissipation plate 43a are reduced by the thermal conductive liquid 463, so that the thermal conduction efficiency of the thermal conductive film 46 in the first direction (i.e., the Z-axis direction) is improved.

In addition to the above embodiments, please continue to refer to fig. 15, in a plane (i.e., XY plane) perpendicular to the first direction, the thermal conductive liquid 463 is further disposed between the inner and outer adjacent portions of the upright graphene film 461 in the upright graphene film 461. Thus, the heat conduction efficiency between the inner and outer adjacent portions of the vertical graphene film 461 extending along the spiral line can be improved, so as to achieve the effect of uniform heating, which is beneficial to improving the heat conduction efficiency from the chip 42 to the heat dissipation plate 43a.

In addition to the above embodiments, the thermal conductive liquid 463 may be disposed between two adjacent vertical graphene film layers 4611 in the vertical graphene film 461, in addition to between two adjacent internal and external vertical graphene films 461 in the vertical graphene film 461. Thus, the heat conduction efficiency between two adjacent vertical graphene film layers 4611 in the vertical graphene film 461 can be improved to achieve the effect of uniform heating, and the heat conduction efficiency from the chip 42 to the heat dissipation plate 43a can also be improved.

Note that, the thermal conductive paste 462 and the thermal conductive liquid 463 may be provided at the same time between at least one end surface of the upright graphene film 461 in the first direction, between two adjacent inner and outer upright graphene films 461 in the upright graphene film 461, and between two adjacent upright graphene film layers 4611 in the upright graphene film 461, which is not particularly limited herein.

In other embodiments, an elastic thermal pad may also be disposed between the inner and outer adjacent upright graphene films 461 in the upright graphene film 461, and between the two adjacent upright graphene film layers 4611 in the upright graphene film 461, at least one end surface of the upright graphene film 461 along the first direction, and the material of the thermal pad includes, but is not limited to, silica gel and foam, so as to reduce the contact thermal resistance and improve the thermal conduction efficiency.

When the thermal conductive film 46 includes the thermal conductive paste 462 and/or the thermal conductive liquid 463, the thermal conductive paste 462 and/or the thermal conductive liquid 463 have fluidity and easily leak and contaminate the internal environment of the electronic device.

To solve the above problem, please refer to fig. 16, and fig. 16 is a schematic structural diagram of a thermal conductive film 46 according to some embodiments of the present application. In this embodiment, the thermal conductive film 46 further includes an encapsulation film 464 in addition to the upright graphene film 461 and the thermal conductive paste 462 and/or the thermal conductive liquid 463. The encapsulation film 464 includes, but is not limited to, a polyethylene terephthalate (PET) film and a metal film. The encapsulating film 464 includes a first encapsulating film portion 464a and a second encapsulating film portion 464b, the first encapsulating film portion 464a and the second encapsulating film portion 464b are respectively located at two opposite sides of the vertical graphene film 461, and the first encapsulating film portion 464a, the vertical graphene film 461, and the second encapsulating film portion 464b are sequentially arranged along a first direction (i.e., a Z-axis direction). In a plane perpendicular to the first direction, an edge of the first encapsulating film portion 464a is located outside a projection of the graphene upright film 461 on the first encapsulating film portion 464a, and an edge of the second encapsulating film portion 464b is located outside a projection of the graphene upright film 461 on the second encapsulating film portion 464 b. One edge of the first encapsulating film portion 464a is connected to one edge of the second encapsulating film portion 464b to encapsulate the upright graphene film 461 between the first encapsulating film portion 464a and the second encapsulating film portion 464 b. Specifically, a periphery of the first encapsulating film portion 464a and a periphery of the second encapsulating film portion 464b may be connected by gluing, and the first encapsulating film portion 464a and the second encapsulating film portion 464b may also be integrally formed, that is, the first encapsulating film portion 464a and the second encapsulating film portion 464b are an integral structural member.

On the basis of the above embodiment, the thermal conductive paste 462 and/or the thermal conductive liquid 463 are located between the first encapsulation film portion 464a and the second encapsulation film portion 464 b. In this way, the thermal paste 462 and/or the thermal liquid 463 may be encapsulated by the encapsulating film 464, and the thermal paste 462 and/or the thermal liquid 463 may be prevented from leaking.

The above describes an embodiment in which the thermal conductive film 46 provided in the present application is applied to the inside of the electronic component 40. In other embodiments, the thermal conductive film 46 provided in any of the embodiments above may also be applied between an electronic component and a shielding cover in a mobile phone, between the shielding cover and a middle frame, between the shielding cover and a circuit board bracket, and between the circuit board bracket and a back cover, and when the electronic device is an electronic device (such as a smart television and a conference screen) with a large volume and an internal space, the thermal conductive film 46 provided in the embodiments of the present application may also be applied between the electronic component and a heat sink, which is not specifically limited in the present application.

It will be appreciated that in other application scenarios, the shape of the thermal membrane 46 may be irregular, other than regular shapes such as circles, squares, rectangles, ovals, triangles, polygons, and the like. For example, referring to fig. 17, fig. 17 is a schematic structural view of a thermal conductive film 46 in an XY plane according to further embodiments of the present application. In the present embodiment, the heat conductive film 46 has a substantially rectangular outline shape, but the lower left corner has an irregular missing corner. The vertical graphene film 461 in the thermal conductive film 46 can be obtained by cutting a rectangular spirally extending vertical graphene film. Therefore, it should be noted that the vertical graphene film 461 in the thermal conductive film 46 provided in the embodiment of the present application is not limited to the vertical graphene film structure continuously extending along a spiral line, but also includes the vertical graphene film structure substantially extending along a spiral line with a cut, and the present application is not limited thereto.

The following describes schematic diagrams of three other application scenarios of the thermal conductive film provided by some embodiments of the present application.

Referring to fig. 18, fig. 18 is a schematic cross-sectional structure view of a circuit board assembly according to some embodiments of the present application. The circuit board assembly includes the above-described circuit board 30, electronic component 40, shield case 50, and heat conductive film 46.

The circuit board 30 has a second surface B.

The electronic component 40 is disposed on the second surface B of the circuit board 30. The electronic component 40 may be the electronic component 40 described in any of the above embodiments, or may be an electronic component having another configuration, and is not particularly limited herein.

The shield can 50 is a metal structure, and the material of the shield can 50 includes, but is not limited to, copper alloy, aluminum alloy, magnesium aluminum alloy, titanium alloy, and the like. The shielding case 50 is used to electromagnetically shield the electronic component 40 and its auxiliary circuits.

In some embodiments, with continued reference to fig. 18, the shield can 50 includes a shield plate 51 and a shield frame 52. The shielding plate 51 is located on the side of the electronic component 40 away from the circuit board 30, and the shielding frame 52 surrounds the periphery of the electronic component 40 and is connected to the shielding plate 51.

In some embodiments, the shielding plate 51 may be a unitary structure or may be formed by assembling a plurality of portions. The shield frame 52 may be a unitary structure or may be formed by assembling a plurality of portions. The shielding frame 52 and the shielding plate 51 may be connected by welding, bonding, or the like, and the shielding frame 52 and the shielding plate 51 may also be integrally formed, that is, the shielding frame 52 and the shielding plate 51 are an integral structural member, which is not limited herein.

The thermal conductive film 46 is the thermal conductive film 46 described in any of the above embodiments. The thermal conductive film 46 is disposed between the electronic component 40 and the shielding plate 51, and the graphene film 461 standing in the thermal conductive film 46 is directed from the electronic component 40 to the shielding plate 51 in the first direction.

Therefore, in the heat conduction membrane, the graphene is vertically arranged, the heat conduction coefficient of the vertically arranged graphene is higher, the heat conduction efficiency from the electronic component to the shielding plate can be improved, and the heat dissipation efficiency of the electronic component is favorably improved.

Referring to fig. 19, fig. 19 isbase:Sub>A schematic cross-sectional view of the electronic device 100 shown in fig. 1 alongbase:Sub>A directionbase:Sub>A-base:Sub>A. The thermal conductive film 46 is disposed between the circuit board assembly and the middle plate 23.

The circuit board assembly includes a circuit board 30, electronic components 40, a shield 50 and a thermal interface material TM.

The circuit board 30 has a second surface B. In some embodiments, the second surface B faces the middle plate 23.

In some embodiments, the shield case 50 includes a shield plate 51 and a shield frame 52. The shielding plate 51 is located on the side of the electronic component 40 away from the circuit board 30, and the shielding frame 52 surrounds the periphery of the electronic component 40 and is connected to the shielding plate 51.

The thermal interface material TM is disposed between the electronic component 40 and the shielding plate 51, and includes, but is not limited to, a thermal paste, a thermal liquid, a thermal pad, or a thermal film according to any of the above embodiments.

Specifically, the thermal conductive film 46 is disposed between the shielding plate 51 and the middle plate 23 of the circuit board assembly, and the thermal conductive film 46 is the thermal conductive film 46 according to any of the above embodiments. The first direction of the upstanding graphene film 461 within the thermally conductive film 46 is directed by the shield plate 51 toward the middle plate 23. The middle plate 23 forms a part of the housing of the electronic apparatus 100, and the heat transferred to the middle plate 23 may be further transferred to the side frame 22 and the screen 10 side.

So, in the heat conduction membrane 46, graphite alkene sets up upright, and the graphite alkene coefficient of heat conductivity of the upright setting is higher, can promote by the heat conduction efficiency of shielding plate 51 to casing, is favorable to promoting circuit board assembly's radiating efficiency.

Referring to fig. 20, fig. 20 is a cross-sectional view of an electronic device according to further embodiments of the present application. In the present embodiment, the electronic apparatus includes the circuit board 30, the electronic component 40, the heat sink 60, and the heat conductive film 46.

The circuit board 30 has a third surface C.

The electronic component 40 is disposed on the third surface C. The electronic component 40 may be the electronic component 40 described in any of the above embodiments, or may be an electronic component with another structure, and is not limited specifically here.

The heat sink 60 is located on a side of the electronic component 40 remote from the circuit board 30. The radiator 60 includes, but is not limited to, a finned radiator and a liquid-cooled radiator. The present embodiment is exemplified by the heat sink 60 being a finned heat sink, which should not be construed as a particular limitation to the present disclosure.

The thermal conductive film 46 is the thermal conductive film according to any of the above embodiments, the thermal conductive film 46 is disposed between the electronic component 40 and the heat sink 60, and the first direction of the graphene film 461 standing in the thermal conductive film 46 is directed from the electronic component 40 to the heat sink 60.

Therefore, in the heat conduction membrane, the graphene is vertically arranged, the heat conduction coefficient of the vertically arranged graphene is higher, the heat conduction efficiency from the electronic component 40 to the radiator 60 can be improved, and the heat radiation efficiency of the electronic component is favorably improved.

The above embodiments describe the structural form of the thermal conductive film 46 and various application scenarios of the thermal conductive film 46, and the following describes a method for manufacturing the thermal conductive film 46.

Referring to fig. 21, fig. 21 is a flowchart of a method for manufacturing a thermal conductive film 46 according to some embodiments of the present disclosure. The method for manufacturing the thermal conductive film 46 is used to manufacture the thermal conductive film 46 according to any of the above embodiments. Specifically, the preparation method may include the following steps S100 to S300.

Step S100: referring to fig. 21 (b), a first material film 461a is provided.

The first material film 461a is made of graphene, graphene oxide, or a mixture of graphene and graphene oxide.

In some embodiments, the material of the first material membrane 461a may be graphene oxide, or a mixture of graphene and graphene oxide. The mechanical strength of the graphene oxide or the mixture of the graphene oxide and the graphene oxide is excellent, subsequent winding operation is facilitated, the graphene oxide or the mixture of the graphene oxide and the graphene oxide can obtain the graphene through reduction reaction, and the heat conduction efficiency can be guaranteed after reduction.

In addition, the first material film 461a may include one first material layer, or may include a plurality of first material layers stacked.

In some embodiments, the first material membrane 461a may comprise a plurality of first material layers arranged in a stack. Thus, the thickness of the first material film 461a is relatively large, and the number of layers to be wound is small on the premise that the vertical columns having the same cross-sectional size are formed by winding in the subsequent winding process, so that the winding efficiency is high.

In some embodiments, referring to fig. 21, before step S100, the preparation method further includes step S100A. Step S100A includes: first, referring to fig. 21 (a), a first material slurry 461d is coated on a substrate C by a coater E; wherein the coating process includes, but is not limited to, at least one of a blade coating process, a roll coating process, a dip coating process, and a spray coating process, and (a) of fig. 21 shows the blade coating process. Then, the first material paste 461d is dried. The drying method includes, but is not limited to, natural drying and dryer drying. Finally, the dried first material paste 461d is peeled off from the substrate C to form a first material layer. The process is simple, the technology is mature, and the operation is convenient.

On the above basis, after step S100A and before step S100, the preparation method may further include: a plurality of first material layers are stacked, and heat conducting paste, heat conducting liquid, or adhesive and the like can be arranged between two adjacent first material layers to fix the relative positions, so as to obtain the first material diaphragm 461a. It should be noted that this step is not required when the first material film comprises a first material layer.

Step S200: referring to fig. 21 (c), a first material film 461a is wound to form a pillar 461b.

Here, the height direction (i.e., Z-axis direction) of the pillar 461b is parallel to the winding axis of the first material film 461a. The step of winding the first material web 461a may be performed on a winder.

In a plane perpendicular to the height direction of the pillar, the first material diaphragm 461a may be wound along a circular spiral line, may also be wound along a square spiral line, may also be wound along a triangular spiral line or a polygonal spiral line, and is not specifically limited herein. This and the following embodiments are exemplified by the first material film 461a being wound in a circular spiral, which should not be construed as a particular limitation to the present invention.

Step S300: referring to fig. 21 (d), the pillar 461b is sliced along a cutting plane to obtain a first material film 461c.

Wherein, the tangent plane is perpendicular with the direction of height of stand (also be Z axle direction), and the instrument of section is cutter D.

In addition, the thickness of the first material film 461c may be 10 micrometers (μm) to 100 μm. Specifically, the thickness of the first material film 461c may be 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, or 100 μm.

The method changes the graphene film arranged at 0 degree into the graphene film arranged at 90 degrees, can ensure the vertical effect of the graphene film, improves the heat conduction efficiency, has simple process and low cost, can be scaled and standardized, and is suitable for commercial production.

When the material of the first material film 461a is graphene, the first material film 461c is a vertical graphene film. When the material of the first material film 461a is graphene oxide or a mixture of graphene oxide and graphene, please refer to (e) in fig. 21, after step S300, the method further includes step S400: the first material film 461c is subjected to reduction treatment to obtain a second material film shown in (f) in fig. 21, that is, the upright graphene film 461. Wherein the reduction reaction may be a thermal reduction reaction at a temperature of 500 ℃. The mechanical strength of the graphene oxide or the mixture of the graphene oxide and the graphene is excellent, the winding operation in the step S200 is facilitated, the graphene oxide or the mixture of the graphene oxide and the graphene is subjected to reduction reaction to obtain the graphene, the heat conductivity of the graphene is excellent, and the heat conduction efficiency can be guaranteed.

On the basis of the above, in order to reduce the contact thermal resistance of the thermal conductive film and improve the thermal conductive efficiency of the thermal conductive film, in some embodiments, referring to (g) of fig. 21, after step S400, the method further includes:

step S500: the thermal conductive paste 462 and/or the thermal conductive liquid 463 are provided at least one end of the vertical graphene film 461 in the extending direction of the winding axis. The thermal paste 462 and/or the thermal liquid 463 may penetrate between two adjacent vertical graphene films 461 in the plane perpendicular to the winding axis, and the vertical graphene films 461 and the thermal paste 462 and/or the thermal liquid 463 are in a relative relationship (see (h) in fig. 21). The thermal conductive paste 462 includes, but is not limited to, a thermal conductive gel or a thermal conductive silicone grease, and the thermal conductive liquid 463 includes, but is not limited to, a lubricating oil, a thermal conductive oil, and other liquid fluids having a thermal conductive function, and a liquid metal containing at least one component of gallium, indium, tin, zinc, and silver. In some embodiments, the thermally conductive liquid 463 is a gallium-based alloy liquid metal. In other embodiments, the thermal paste 462 and/or the thermal liquid 463 may not penetrate between the inner and outer adjacent two portions of the graphene film 461.

Thus, the thermal conductive paste 462 and/or the thermal conductive liquid 463 can reduce the contact thermal resistance and improve the thermal conductive efficiency.

The structural form, the application scenario, and the preparation method of the thermal conductive film 46 provided in the embodiments of the present application are described in the above embodiments, and the thermal conductive performance of the thermal conductive film 46 provided in the present application is tested through a comparative test. Referring to fig. 22, fig. 22 is a schematic structural diagram of a thermal conductivity testing system according to the present application. The thermal conductivity test system includes a heat source 70, a thermal interface structure 80, and a heat sink 60. The heat source 70 is a ceramic heating sheet, and the heating power is controlled. The heat sink 60 is a water-cooled copper block, which keeps the heat sink 60 in a room temperature environment. The thermal interface structure 80 is the structure described in comparative example 1 and comparative example 2 below, and example 1, example 2, and example 3 of the present application, respectively. Referring to fig. 23, fig. 23 is a graph illustrating the temperature value measured at the center point O of the surface of the heat source 70 facing away from the thermal interface structure 80 in the test system of fig. 22 by using a temperature sensor (which may be a contact thermocouple) as a function of the power density of the heat source 70.

Comparative example 1

See fig. 24 for a structure of a planar graphene film. The preparation method comprises the following steps: uniformly coating the graphene oxide slurry on a substrate by using a coating machine, naturally drying, and stripping to obtain a 120-micron graphene oxide film; the graphene oxide film was thermally reduced at a temperature of 500 ℃ to obtain the planar graphene film, which was used as the thermal interface structure 80, and the test results are shown in fig. 23. The heating ceramic plate temperature when using the planar graphene film was 67.4 ℃ at a power density of 10W/cm 2 and an initial temperature of 22 ℃.

Comparative example 2

A thermally conductive silicone grease. The test results are shown in fig. 23. When the power density is 10W/cm 2 and the initial temperature is 22 ℃, the temperature of the heating ceramic plate when the heat-conducting silicone grease is used is 78.6 ℃.

Example 1

Please refer to fig. 25 for a structure of the vertical graphene film. The preparation method comprises the following steps: uniformly coating the graphene oxide slurry on a substrate by using a coating machine, naturally drying, and stripping to obtain a 50-micrometer graphene oxide film; winding the graphene oxide film into cylindrical graphene through a winding machine, and cutting the cylindrical graphene into a vertical graphene oxide film with the thickness of 120 mu m through a rotary low-temperature slicer; and (3) putting the vertical graphene oxide film at the temperature of 500 ℃ for thermal reduction to obtain the vertical graphene oxide film. The vertical graphene film is directly used as the thermal interface structure 80, and the heat conduction test result is shown in fig. 23, when the power density is 10W/cm 2 and the initial temperature is 22 ℃, the temperature of the heating ceramic wafer when the vertical graphene film is used is 50.5 ℃, and the heat dissipation effect is better than that of a planar graphene film and heat conduction silicone grease.

Example 2

A vertical graphene film comprising a liquid metal. The preparation method comprises the following steps: uniformly coating the graphene oxide slurry on a substrate by using a coating machine, naturally drying, and stripping to obtain a 50-micrometer graphene oxide film; winding the graphene oxide film into cylindrical graphene through a winding machine, and cutting the cylindrical graphene into an upright graphene oxide film with the thickness of 80 microns through a rotary low-temperature slicer; placing the vertical graphene oxide film at the temperature of 500 ℃ for thermal reduction to obtain a vertical graphene film; and finally, coating a layer of liquid metal with the thickness of 20 mu m on the upper surface and the lower surface of the vertical graphene film to obtain the vertical graphene film containing the liquid metal. A vertical graphene film containing a liquid metal was used as the thermal interface structure 80, and the test results are shown in fig. 23. When the power density is 10W/cm 2 and the initial temperature is 22 ℃, the temperature of the heating ceramic wafer is 35.7 ℃ when the vertical graphene film containing the liquid metal is used, and the heat dissipation effect is better than that of a plane graphene film and heat-conducting silicone grease.

Example 3

A vertical graphene membrane comprising a thermally conductive silicone grease. The preparation method comprises the following steps: uniformly coating the graphene oxide slurry on a substrate by using a coating machine, naturally drying, and stripping to obtain a 50-micrometer graphene oxide film; winding the graphene oxide film into cylindrical graphene through a winding machine, and cutting the cylindrical graphene into an upright graphene oxide film with the thickness of 80 mu m through a rotary low-temperature slicer; placing the vertical graphene oxide film at the temperature of 500 ℃ for thermal reduction to obtain a vertical graphene film; and finally coating a layer of heat-conducting silicone grease with the thickness of 20 microns on the upper surface and the lower surface of the vertical graphene film to obtain the vertical graphene film containing the heat-conducting silicone grease. A vertical graphene film containing a thermally conductive silicone grease was used as the thermal interface structure 80, and the test results are shown in fig. 23. When the power density is 10W/cm 2 and the initial temperature is 22 ℃, the temperature of the heating ceramic wafer is 41.2 ℃ when the vertical graphene film containing the heat-conducting silicone grease is used, and the heat dissipation effect is better than that of a plane graphene film and the heat-conducting silicone grease.

According to the experiment, the heat conduction effect of the heat conduction film is excellent, and the heat dissipation efficiency can be improved. The thermal conductivity of the thermal conductive film provided by the application is 2-4 times that of the planar graphene film shown in comparative example 1.

The particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A thermally conductive film comprising a vertical graphene film extending in a first direction, wherein the vertical graphene film extends along a spiral line in a plane perpendicular to the first direction.

2. The heat conductive film according to claim 1, further comprising a heat conductive paste and/or a heat conductive liquid;

the heat conducting paste and/or the heat conducting liquid are/is arranged on at least one end face of the vertical graphene film along the first direction.

3. The thermally conductive film of claim 2, wherein the thermally conductive paste and/or fluid is further disposed between two adjacent inner and outer portions of the graphene film in a plane perpendicular to the first direction.

4. The heat transfer film of claim 2, wherein the heat transfer paste is a heat transfer gel or a heat transfer silicone grease, and the heat transfer liquid is a lubricant, a heat transfer oil, or a liquid metal containing at least one of gallium, indium, tin, zinc, and silver.

5. A thermally conductive film as claimed in claim 2, further comprising an encapsulating film, wherein the encapsulating film comprises a first encapsulating film portion and a second encapsulating film portion, and the first encapsulating film portion, the upright graphene film, and the second encapsulating film portion are sequentially arranged along the first direction; the heat conducting paste and/or the heat conducting liquid are/is positioned between the first packaging film part and the second packaging film part;

in a plane perpendicular to the first direction, an edge of the first encapsulating film portion is located outside a projection of the upright graphene film on the first encapsulating film portion, and an edge of the second encapsulating film portion is located outside a projection of the upright graphene film on the second encapsulating film portion; the edge of the first packaging film part is connected with the edge of the second packaging film part in a circle.

6. The thermally conductive film of any of claims 1-5, wherein the graphene upright film comprises a plurality of graphene upright film layers disposed in a stack.

7. An electronic component, comprising:

a substrate having a first surface;

a chip disposed on the first surface;

the heat dissipation frame comprises a heat dissipation plate, and the heat dissipation plate is positioned on one side of the chip, which is far away from the substrate;

the heat conduction film according to any one of claims 1 to 6, wherein the heat conduction film is disposed between the chip and the heat dissipation plate, and a first direction of the graphene film standing in the heat conduction film is directed from the chip to the heat dissipation plate.

8. A circuit board assembly, comprising:

a circuit board having a second surface;

the electronic component is arranged on the second surface;

the shielding cover comprises a shielding plate, and the shielding plate is positioned on one side of the electronic component far away from the circuit board;

the thermal conductive film according to any one of claims 1 to 6, which is disposed between the electronic component and the shielding plate, wherein a first direction of the graphene film standing in the thermal conductive film is directed from the electronic component to the shielding plate.

9. An electronic device, comprising:

a circuit board assembly comprising a circuit board, an electronic component, a shield can, and a thermal interface material, wherein,

the circuit board is provided with a second surface;

the electronic component is arranged on the second surface;

the shielding case comprises a shielding plate, and the shielding plate is positioned on one side of the electronic component far away from the circuit board;

the thermal interface material is arranged between the electronic component and the shielding plate;

the shell is positioned on one side of the shielding plate far away from the circuit board;

the thermal conductive film of any one of claims 1-6, disposed between the shielding plate and the housing, wherein a first direction of the graphene film standing within the thermal conductive film is directed from the shielding plate to the housing.

10. An electronic device, comprising:

a circuit board having a third surface;

an electronic component disposed on the third surface;

the radiator is positioned on one side of the electronic component, which is far away from the circuit board;

the thermal conductive film according to any one of claims 1 to 6, wherein the thermal conductive film is disposed between the electronic component and the heat sink, and a first direction of the graphene film standing in the thermal conductive film is directed from the electronic component to the heat sink.

11. A method for preparing a heat-conducting film is characterized by comprising the following steps:

slicing the upright column along a section to obtain a first material film; wherein, the tangent plane is perpendicular with the direction of height of stand.

12. The preparation method according to claim 11, wherein the material of the first material membrane is graphene oxide or a mixture of graphene oxide and graphene;

after obtaining the first material film, the preparation method further includes:

and carrying out reduction treatment on the first material film to obtain a second material film, wherein the second material film is an upright graphene film.

13. The method according to claim 12, characterized in that, after said obtaining of the second material film, the method further comprises:

and a heat conductive paste and/or a heat conductive liquid is provided on at least one end in the extending direction of the second material film around the axis.

14. The manufacturing method according to any one of claims 11 to 13, wherein the first material membrane includes a plurality of first material layers arranged in a stacked manner, and the material of the first material layers is graphene, graphene oxide, or a mixture of graphene and graphene oxide.