WO2014036739A1

WO2014036739A1 - Thermal conductor

Info

Publication number: WO2014036739A1
Application number: PCT/CN2012/081198
Authority: WO
Inventors: 吴晓宁
Original assignee: 北京中石伟业技术有限公司
Priority date: 2012-09-10
Filing date: 2012-09-10
Publication date: 2014-03-13

Abstract

A thermal conductor comprises a graphite film and a metal sheet. The graphite film and the metal sheet are formed as a laminated body. The thermal conductor is easy to process, convenient to use, not limited to installation location, and facilitates high integration of devices and development of ultra-small and ultra-thin technology.

Description

Thermal conductor

The present invention relates to a heat conducting device, and more particularly to a heat conductor. Background technique

Thermal design is a specialized discipline that focuses on the transfer or maintenance of heat in equipment. In the heat transfer design, it is often necessary to select the heat transfer medium reasonably. It is necessary to consider not only the heat transfer efficiency and heat transfer capacity of the heat sink, but also the factors such as optimizing its shape design and outer surface area to improve the overall heat dissipation efficiency of the heat transfer system. .

At the same time, with the rapid development of technology, electronic and optoelectronic products are moving towards light, thin, short, small and high power. Such development will increase the heat density of electronic and optoelectronic products, leading to an increase in power loss. Therefore, the demand for electronic and optoelectronic products with high heat dissipation efficiency has also increased significantly.

Especially with the popularization of ultra-thin equipment and outdoor equipment, in many occasions where direct cooling of the fan is not allowed, such as: wireless communication outdoor base station, automobile electronic unit and smart phone, etc., often multiple heat-generating devices share one heat sink This will cause a serious imbalance in the temperature gradient inside the heat sink, which greatly affects the efficiency of the heat sink and limits the speed and power of the electronic device.

Graphite film is a new type of heat-conducting heat-dissipating material with unique grain orientation and uniform heat conduction in two directions. The layered structure can be well adapted to any surface. Patent not disclosed in the applicant

In EP12158250.6, a method for manufacturing a graphite film is proposed. The method uses a polymer film as a raw material film, and a plurality of raw material films are stacked and filled in a charging container, so that the raw material film is heat-treated in a vertical state. A graphite film was obtained. Summary of the invention

In view of the above, it is an object of the present invention to provide a heat conductor which can increase the heat transfer speed of the heat conductor and allow the heat of the heat generating device to be transferred to the heat sink member faster.

Based on the above object, the present invention provides a heat conductor including a graphite film and a metal A sheet, wherein the graphite film and the metal sheet are formed into a laminate.

Alternatively, the graphite film and the metal sheet are alternately closely laminated.

Preferably, the number of layers to be laminated is not less than 3 layers.

Alternatively, the graphite film and the metal sheet are laminated together by a thermally conductive adhesive.

Preferably, the thermally conductive adhesive is any one selected from the group consisting of a thermally conductive epoxy resin adhesive, an acrylic resin thermal epoxy resin adhesive, and a silicon thermal conductive adhesive.

Preferably, the thermally conductive epoxy resin adhesive is any one selected from the group consisting of a room temperature vulcanization thermally conductive epoxy resin adhesive and a high temperature vulcanization thermal conductive epoxy resin adhesive.

Optionally, the graphite film is an artificial graphite film obtained by heat-treating a polymer film.

Preferably, the graphite film has a thickness of about 0.01 to 0.2 mm.

Preferably, the polymer film is selected from the group consisting of polyoxadiazole, polyimide, polyparaphenylene vinylene, polybenzimidazole, polybenzoxazole, polybenzobisoxazole, polythiazole, poly At least one of a film of benzothiazole, polybenzobisthiazole, and polyamide.

Optionally, the metal sheet has a thickness of about 0.01 mm to 1 mm.

Preferably, the metal sheet is a metal foil.

Preferably, the metal foil is selected from at least one of an aluminum foil and a copper foil.

Optionally, the surface of the heat conductor is provided with a heat conductive adhesive for contacting the heat conductor with the heat generating device.

Preferably, the surface of the heat conductor is further provided with a release paper.

As can be seen from the above, the heat conductor provided by the present invention utilizes the high thermal conductivity of the graphite film (planar thermal conductivity of about 1500 W/mK), and is laminated with the metal sheet through the graphite film to rapidly heat the surface of the graphite film. Propagation, the temperature of the surface of the graphite film quickly reaches equilibrium, so that the heat of the metal sheet is evenly distributed, and finally the heat balance is achieved in the heat sink member. Thereby, the temperature gradient on the heat conduction path is reduced or eliminated, the temperature of the heat generating device is lowered, the temperature unbalanced hot spot region inside the device is eliminated, and the overall reliability and long-term working ability of the device and the device are improved. Moreover, the heat conductor provided by the invention is easy to process, convenient to use, and free from the installation position, and is designed for the heat conduction requirements of the device in recent years, and is suitable for various environments and requirements; the heat conduction speed is fast, and the effective heat transfer path length is shortened. It overcomes the problem of internal temperature gradient of the heat sink component caused by high heat-generating components; it provides a powerful help for the high integration of equipment and the development of ultra-small and ultra-thin. DRAWINGS 1 is a schematic structural view of a heat conductor according to Embodiment 1 of the present invention;

2 is a schematic structural view of a heat conductor according to Embodiment 2 of the present invention;

3 is a schematic structural view of a heat conductor according to Embodiment 3 of the present invention;

4 is a schematic structural view of a heat conductor according to Embodiment 4 of the present invention;

Figure 5 is a schematic structural view of a heat conductor according to Embodiment 5 of the present invention;

6 is a schematic structural view of a heat conductor according to Embodiment 6 of the present invention;

7 is a schematic view showing a state of use of a heat conductor according to Embodiment 6 of the present invention;

8 is a schematic view showing another use state of the heat conductor according to Embodiment 6 of the present invention;

Figure 9 is a schematic view showing the structure of a heat conductor according to Embodiment 7 of the present invention. detailed description

In order to make the objects, the technical solutions and the advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the accompanying drawings.

The present invention provides a heat conductor comprising a graphite film and a metal sheet, wherein the graphite film and the metal sheet are formed into a laminate.

Preferably, the number of layers to be laminated is not less than 3 layers. Example 1

Referring to Figure 1, there is shown a schematic structural view of a heat conductor according to Embodiment 1 of the present invention. As an embodiment of the present invention, the heat conductor includes a first graphite film 101, a first metal sheet 201, a second graphite film 102, and a second metal sheet 202, wherein the first graphite film 101 and the first metal sheet The material 201, the second graphite film 102, and the second metal sheet 202 are laminated in this order.

When any one of the first graphite film 101 and the second graphite film 102 receives heat, the heat is rapidly conducted laterally on the graphite films 101 and 102, and the heat diffused on the graphite films 101 and 102 toward the metal sheet 201 Longitudinal heat transfer is performed with 202, so that the inside of the metal sheets 201 and 202 also undergo longitudinal heat transfer. Therefore, the present invention shortens the heat transfer path of the heat conductor and allows the heat to be quickly and uniformly distributed.

When the heat-generating device is connected to the heat sink member by the heat conductor provided by the present invention, heat of the heat-generating device is quickly transmitted to the heat sink member through the heat-conducting member, which can effectively shorten the heat conduction path, increase the heat transfer speed, and quickly achieve heat balance inside the device. Eliminate the temperature imbalance inside its hot spot area.

In the case where a plurality of heat generating devices share the same heat sink device, each heat generating device is passed through The heat conductor is connected to the heat sink member to reduce a temperature gradient caused by a plurality of hot spots inside the heat sink member. Example 2

Referring to Fig. 2, it is a schematic structural view of a heat conductor according to Embodiment 2 of the present invention. As an embodiment of the present invention, the heat conductor includes a first graphite film 101, a first metal sheet 201, a second graphite film 102, a third graphite film 103, and a second metal sheet 202, wherein the first graphite film 101. The first metal sheet 201, the second graphite film 102, the third graphite film 103, and the second metal sheet 202 are sequentially layered. When any one of the graphite films 101, 102, and 103 receives heat, the heat is rapidly in the graphite. Lateral conduction is performed on the films 101, 102, and 103, and the diffused heat is transferred to the metal sheets 201 and 202, so that the heat of the metal sheets 201 and 202 is evenly distributed. Therefore, the present invention shortens the heat transfer path of the heat conductor and allows the heat to be quickly distributed evenly.

It should be noted that the mode of use of the present invention is not limited to the manner of use in Embodiment 1, and the heat conductor may be disposed on the surface of the heat sink member, and the high thermal conductivity of the graphite film is utilized to rapidly dissipate heat on the surface of the heat sink member. Conduct heat transfer and achieve heat balance in the heat sink, thereby reducing the heat conduction path inside the heat sink, increasing the heat dissipation speed of the heat sink, reducing or eliminating the temperature gradient on the heat conduction path, lowering the temperature of the heat generating device, and eliminating the temperature inside the device. Unbalanced hotspot areas improve overall reliability and long-term performance of devices and equipment. Example 3

Referring to FIG. 3, it is a schematic structural view of a heat conductor according to Embodiment 3 of the present invention. As an embodiment of the present invention, the heat conductor includes a first metal sheet 201, a first graphite film 101, and a second metal sheet 202, wherein the first metal sheet 201, the first graphite film 101, and the second metal The sheets 202 are laminated in this order.

When any portion of the first graphite film 101 receives the heat transferred from the first metal sheet 201, the heat is rapidly conducted laterally on the first graphite film 101, and the heat diffused on the first graphite film 101 is directed to the first The two metal sheets 202 are longitudinally heat-transferred such that the interior of the second metal sheet 202 also undergoes longitudinal heat transfer. Therefore, the present invention shortens the heat transfer path of the heat conductor and allows the heat to be quickly and evenly distributed. In order to further increase the heat transfer rate of the heat conductor and fully utilize the utilization rate of the graphite film, the present embodiment achieves the closeness of the two between the laminated graphite film and the metal sheet by the heat conductive adhesive on the basis of the first embodiment. Attached.

Referring to FIG. 4, it is a schematic structural view of a heat conductor according to Embodiment 4 of the present invention. The heat conductor includes a first graphite film 101, a first metal sheet 201, a second graphite film 102, and a second metal sheet 202, wherein the first graphite film 101, the first metal sheet 201, and the second graphite film 102 The second metal sheets 202 are laminated in this order. Further, between the first graphite film 101 and the first metal sheet 201, between the first metal sheet 201 and the second graphite film 102, between the second graphite film 102 and the second metal sheet 202 Thermally conductive adhesives 301 are provided to keep adjacent layers intimately attached.

Preferably, the thermally conductive epoxy resin adhesive is any one selected from the group consisting of a room temperature vulcanization thermally conductive epoxy resin adhesive and a high temperature vulcanization thermal conductive epoxy resin adhesive. Example 5

Of course, the position at which the thermally conductive adhesive 301 is disposed is not limited to the graphite film and the metal sheet. If the adjacent layers are graphite films laminated to each other, a thermally conductive adhesive may be provided between the graphite films.

Referring to FIG. 5, it is a schematic structural view of a heat conductor according to Embodiment 5 of the present invention. In this embodiment, on the basis of the second embodiment, a thermally conductive adhesive 301 is disposed between adjacent layers, wherein a thermally conductive adhesive 301 is also disposed between the second graphite film 102 and the third graphite film 103. . Example 6

In many cases, the surface area of the heat sink member is larger than the surface area of the heat generating device. When the heat conductor provided by the present invention is used, part of the heat conductor cannot be in close contact with the heat sink member, which may affect the heat conduction effect of the heat conductor. In order to further increase the heat transfer rate of the heat conductor, the utilization ratio of the graphite film in the heat conductor is sufficiently exhibited. In the present embodiment, the heat conductor is in contact with the heat sink member and/or the heat generating device through the heat conductive adhesive.

Referring to Fig. 6, there is shown a schematic structural view of a heat conductor according to Embodiment 6 of the present invention. In the embodiment, on the basis of the third embodiment, a thermal conductive adhesive is disposed between the first metal sheet 201 and the first graphite film 101 and between the first graphite film 101 and the second metal sheet 202. 301, and a thermal conductive adhesive 302 is disposed on the surface of the thermal conductor, and the thermal conductor is dispersed by the thermal conductive adhesive 302. The thermal device and/or the heat generating device achieve close contact, fully utilize the utilization rate of the heat conductor, and increase the speed of heat transfer between the heat conductor and the heat generating device and the heat sink member.

It should be noted that the position at which the thermally conductive adhesive 302 is disposed is not limited to one side of the heat conductor shown in the drawing, and a thermally conductive adhesive may be provided on the other side.

Of course, based on the fourth embodiment and the fifth embodiment, a heat conductive adhesive may be disposed on the surface of the heat conductor to keep the heat conductor in close contact with the device.

Referring to Figure 7, there is shown a schematic view of a state of use of a heat conductor according to Embodiment 6 of the present invention. After the heat conductive adhesive 302 is disposed on the side of the heat conductor 4, the two side faces of the heat conductor 4 are in close contact with the heat generating device 5 and the heat sink member 6, respectively. Thus, the heat conductor 4 which is not in contact with the heat generating device 5 can also maintain close contact with the heat sink member 6, and the utilization of the heat conductor 4 can be improved during heat transfer.

Referring to Fig. 8, there is shown another schematic view of a state of use of the heat conductor according to Embodiment 6 of the present invention. In the case where the plurality of heat generating devices 5 share the same heat sink member 6, the heat conductor 4 is adhered to the surface of the heat sink member 6, and the plurality of heat generating devices 5 are closely connected to the heat sink member 6 by mechanical pressing.

If the heat generating device and the heat sink member cannot be closely connected by the heat conductor due to the spatial position, the heat conductor may be respectively adhered to the heat generating device and the heat sink member, so that the heat generating device and the heat sink member are connected at a long distance, and the heat passes through the heat conductor. At the same time, it is transferred from the heat generating device to the heat sink member, so that the heat transfer system can quickly reach equilibrium. Example 7

Referring to FIG. 9, which is a schematic structural view of a heat conductor according to Embodiment 7 of the present invention, in order to facilitate the use of the heat conductor provided by the present invention, the embodiment is further provided on the surface of the heat conductive adhesive 302 on the basis of Embodiment 6. There is a release paper 303.

In use, it is only necessary to remove the release paper 303 on the surface of the heat conductor, and the heat conductor can be adhered to any surface of the device or the heat sink member that needs to be thermally conductive, so that heat is quickly conducted on the heat conductor, and the inside of the heat sink member is eliminated. Temperature imbalance hotspot area. Due to the popularity of ultra-thin devices, the number of stacked graphite films and metal sheets and the lamination order can be set as needed. The thickness of the graphite film and the metal sheet can also be selected as needed. If necessary, the heat conductor can also be bent and placed in the device for heat conduction. Therefore, the present invention can meet the structural requirements of various devices and can be applied to various ultra-thin or non-flat device structures.

Optionally, the graphite film is an artificial graphite film obtained by heat-treating a polymer film. Preferably, the graphite film has a thickness of about 0.01 to 0.2 mm.

Optionally, the metal sheet has a thickness of about 0.01 mm to 1 mm.

Preferably, the metal sheet is a metal foil.

Preferably, the metal foil is at least one selected from the group consisting of aluminum foil and copper foil.

As described above, the heat conductor provided by the present invention can simultaneously increase the speed at which the heat generating device transfers heat to the heat body and the speed at which the heat conductor transfers heat to the heat sink member, thereby improving the heat dissipation speed of the heat generating device and eliminating the temperature imbalance hotspot inside the device. Areas that improve the overall reliability and long-term ability of devices and equipment.

The heat conductor provided by the invention utilizes a graphite film with high thermal conductivity (planar thermal conductivity of about 1500 W/mK), and is laminated with a metal sheet through a graphite film, so that heat is rapidly transmitted on the surface of the graphite film, and the temperature of the surface of the graphite film is fast. The balance is achieved, the heat of the metal sheet is evenly distributed, and finally the heat balance is achieved in the heat sink member. Thereby, the temperature gradient on the heat conduction path is reduced or eliminated, the heat dissipation efficiency of the heat sink member is greatly improved, the temperature of the device is lowered, the temperature imbalance inside the device is eliminated, and the overall reliability and long-term working ability of the device and the device are improved.

Moreover, the heat conductor provided by the invention is easy to process, convenient to use, and free from the installation position, and is designed in recent years for the heat conduction requirement of the device, and is suitable for various environments and requirements; the heat conduction speed is fast, and the effective heat transfer path length is shortened. It overcomes the problem of internal temperature gradient of the heat sink component caused by high heat-generating components; it provides a powerful help for the high integration of equipment and the development of ultra-small and ultra-thin.

It should be understood by those skilled in the art that the above description is only the embodiment of the present invention, and is not intended to limit the invention, and any modifications, equivalents, and improvements made within the spirit and principles of the present invention. And so on, should be included in the scope of protection of the present invention.

Claims

Claim

A heat conductor comprising a graphite film and a metal sheet, wherein the graphite film and the metal sheet are formed into a laminate.

The heat conductor according to claim 1, wherein the graphite film and the metal sheet are alternately closely laminated.

The heat conductor according to claim 2, wherein the number of layers of the heat conductor stacked is not less than three.

The heat conductor according to claim 1, wherein the graphite film and the metal sheet are laminated together by a heat conductive adhesive.

The heat conductor according to claim 4, wherein the heat conductive adhesive is any one selected from the group consisting of a thermally conductive epoxy resin adhesive, an acrylic resin thermal conductive adhesive, and a silicon thermal conductive adhesive. One.

The heat sink according to claim 5, wherein the thermally conductive epoxy resin adhesive is any one selected from the group consisting of a room temperature vulcanization thermally conductive epoxy resin adhesive and a high temperature vulcanization thermal conductive epoxy resin adhesive. One.

The heat conductor according to claim 1, wherein the graphite film is an artificial graphite film obtained by subjecting a polymer film to heat treatment.

The heat conductor according to claim 7, wherein the graphite film has a thickness of 0.01 to 0.2 mm.

The heat conductor according to claim 7, wherein the polymer film is selected from the group consisting of polyoxadiazole, polyimide, polyparaphenylene vinylene, polybenzimidazole, polybenzoxazole At least one of a film of azole, polybenzobisoxazole, polythiazole, polybenzothiazole, polybenzobisthiazole, and polyamide.

The heat conductor according to claim 1, wherein the metal sheet has a thickness of 0.01 to 1 mm.

The heat conductor according to claim 10, wherein the metal sheet is a metal foil.

The heat conductor according to claim 11, wherein the metal foil is at least one selected from the group consisting of aluminum foil and copper foil.

The heat conductor according to any one of claims 1 to 12, wherein a surface of the heat conductor is provided with a heat conductive adhesive, and the heat conductive adhesive is used to heat the heat conductor Device Piece of contact.

The heat conductor according to claim 13, wherein the surface of the heat conductor is further provided with a release paper.