KR102095815B1 - Thermal diffusion sheet - Google Patents

Abstract

Heat diffusion sheet according to an embodiment of the present invention, a graphene layer containing graphene; And an elastic material layer positioned on one surface of the graphene layer and having elasticity.

Description

Heat diffusion sheet {THERMAL DIFFUSION SHEET}

The present invention relates to a heat diffusion sheet, and more particularly, to a heat diffusion sheet with improved structure.

In various electronic devices, a heat diffusion sheet is used to dissipate heat generated from electronic components. In general, the heat diffusion sheet is composed of a graphite sheet having excellent thermal conductivity in a direction parallel to the surface, that is, in a plane.

However, the graphite sheet has low strength, severe cracks, and heat conduction only in the direction in the plane, making it difficult to effectively dissipate heat. In addition, since it has conductivity, a separate insulating layer for insulating the graphite sheet should be positioned. Since it is difficult to directly form a separate insulating layer on the graphite sheet, it is bonded after placing the adhesive layer between the graphite sheet and the insulating layer. . At this time, in order to insulate the graphite sheet, an adhesive layer and an insulating layer should be located on both sides of the graphite sheet, and a separate adhesive layer for bonding with the electronic device should be provided. Accordingly, the heat diffusion sheet has a stacked structure of at least six layers. Moreover, in order to increase the heat dissipation properties, it is necessary to increase the thickness of the graphite sheet, so it is difficult to manufacture a heat diffusion sheet having excellent heat dissipation properties and a thin thickness.

The present invention is to provide a heat spreading sheet having a thin thickness while having excellent heat dissipation characteristics.

Heat diffusion sheet according to an embodiment of the present invention, a graphene layer containing graphene; And an elastic material layer positioned on one surface of the graphene layer and having elasticity.

The elastic material layer may include an elastic material composed of rubber.

The elastic material may include ethylene-propylene-diene rubber (EPDM).

The elastic material layer may further include a heat dissipation material.

The heat dissipation material of the elastic material layer may include graphene, carbon nanotubes, or graphite.

With respect to 100 parts by weight of the elastic material layer, the elastic material may be included by 50 to 95 parts by weight, and the heat dissipation material may be included by 5 to 50 parts by weight.

The thickness of the graphene layer may be greater than the thickness of the elastic material layer.

The graphene layer may have a thickness of 5 μm to 200 μm, and the elastic material layer may have a thickness of 5 μm to 200 μm.

Located on the other side of the graphene layer may include a resin layer containing a thermoplastic resin.

The resin layer may further include a heat dissipation material.

The heat dissipation material of the resin layer may include graphene, carbon nanotubes, or graphite.

With respect to 100 parts by weight of the resin layer, the thermosetting resin may be included by 40 to 95 parts by weight, and the heat dissipation material may be included by 5 to 60 parts by weight.

The thickness of the graphene layer may be greater than the thickness of the resin layer.

The thickness of the graphene layer may be 5 μm to 200 μm, and the thickness of the resin layer may be 5 μm to 200 μm.

An adhesive portion may be positioned on the resin layer.

The adhesive portion may include a support layer formed on the resin layer and an adhesive layer formed on the support layer.

A resin layer including a thermoplastic resin may be included between one surface of the graphene layer and the elastic material layer.

A heat diffusion sheet according to another embodiment of the present invention includes a graphene layer including graphene; And a resin layer located on at least one surface of the graphene layer and including a thermoplastic resin.

The resin layer may further include a heat dissipation material.

The heat dissipation material may include graphene, the width of the heat dissipation material may be 1 μm to 20 μm, and the thickness may be 1 nm to 100 nm.

The heat spreading sheet according to an embodiment of the present invention is attached to parts of various electronic devices (for example, display devices, etc.) so that heat dissipation of the electronic devices is effectively performed. At this time, the heat diffusion sheet according to the present embodiment includes a graphene layer having excellent heat diffusion properties, an elastic material layer having excellent durability and heat dissipation properties is formed on one surface of the graphene layer, and graphene is formed on the other surface of the graphene layer. A resin layer having excellent heat dissipation properties while removing defects in the pin layer is formed. Thereby, the heat-diffusion sheet can have a simple structure and a small thickness, and have excellent durability and heat dissipation characteristics. In addition, the heat-diffusion sheet has flexible characteristics and can be applied to various electronic products.

1 is a cross-sectional view showing a heat diffusion sheet according to an embodiment of the present invention.
2A to 2E are cross-sectional views illustrating a method of manufacturing a heat diffusion sheet 100 according to an embodiment of the present invention.
3 is a cross-sectional view showing a heat diffusion sheet according to another embodiment of the present invention.
4 is a cross-sectional view showing a heat diffusion sheet according to another embodiment of the present invention.
5 is a cross-sectional view showing a heat diffusion sheet according to another embodiment of the present invention.
6 is a cross-sectional view showing a heat diffusion sheet according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the present invention is not limited to these embodiments and can be modified in various forms.

In the drawings, in order to clearly and briefly describe the present invention, illustration of parts irrelevant to the description is omitted, and the same reference numerals are used for the same or extremely similar parts throughout the specification. In addition, in the drawings, the thickness and the area are enlarged or reduced in order to make the description more clear. The thickness and area of the present invention are not limited to those shown in the drawings.

In addition, when a part is “included” in another part of the specification, the other part is not excluded and other parts may be further included, unless otherwise stated. In addition, when a part such as a layer, film, region, plate, etc. is said to be "above" another part, this includes not only the case where the other part is "just above" but also another part in the middle. When a part such as a layer, a film, a region, or a plate is said to be "directly above" another part, it means that no other part is located in the middle.

Hereinafter, a heat diffusion sheet according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a heat diffusion sheet according to an embodiment of the present invention.

Referring to FIG. 1, the heat diffusion sheet 100 according to the present embodiment includes a graphene layer 10 and an elastic material layer 20 positioned on one surface of the graphene layer 10 and having elasticity. And it may further include a resin layer 30 and the adhesive portion 40 located on the other surface of the graphene layer 10. This will be explained in more detail.

The graphene layer 10 may have flat surfaces on both sides of the electronic component or the like. Graphene is composed of carbon atoms in a sp? Hybrid mode with a two-dimensional two-dimensional hexagonal lattice arrangement, and has excellent heat diffusion properties. Thereby, heat diffusion by the graphene layer 10 can be effectively performed.

The graphene layer 10 may be formed of a single graphene sheet, or may be formed by stacking a plurality of single graphene sheets. Here, the single graphene sheet may be formed of a single-layer graphene layer or a sheet formed by stacking fewer than ten graphene layers of the above-described single layer. This single graphene sheet can be produced by various methods. For example, graphene can be obtained through micromechanical exfoliation from highly oriented pyrographite (HOPG). Alternatively, graphene can be obtained by heating silicon carbide (SiC) at a high temperature. Alternatively, graphene may be synthesized through a chemical vapor deposition (CVD) on a metal base layer. Alternatively, graphene may be obtained by chemical treatment or high temperature treatment using graphite inserted as a precursor. Alternatively, graphene can be obtained by dipping a graphite product in a liquid and applying ultrasonic waves to the atmospheric temperature. Graphene can be synthesized by various other methods to produce a single graphene sheet. As an example, the single graphene sheet described above may have a thickness of 10 nm or less (eg, 1 nm to 10 nm). When the thickness of a single graphene sheet exceeds 10 nm, it may be difficult to act as a single graphene sheet having graphene properties. However, the present invention is not limited thereto, and the thickness of a single graphene sheet may be variously modified.

For example, the thickness T1 of the graphene layer 10 d according to the present embodiment including one or a plurality of single graphene sheets may be 5 μm to 200 μm. That is, in the present embodiment, the graphene layer 10 may have a sufficient thickness by stacking a plurality of graphene sheets. If the thickness (T1) of the graphene layer 10 is less than 5 μm, the graphene layer 10 may be damaged and graphene in various processes such as a process of forming the resin layer 20 (for example, a roll-to-roll process) The fin layer 10 may be difficult to have sufficient heat dissipation characteristics. When the thickness T1 of the graphene layer 10 exceeds 200 μm, thinning of the heat diffusion sheet 100 may be difficult.

At this time, the thickness (T1) of the graphene layer 10 may vary depending on the application field of the heat diffusion sheet 100. For example, when the heat diffusion sheet 100 is applied to a mobile phone or the like, the thickness of the graphene layer 10 may be limited so that the portability can be improved, so that the thickness T1 of the graphene layer 10 is 5 μm to 150 μm (eg , 5㎛ to 100㎛). As another example, when the heat diffusion sheet 100 is applied to a large product such as a television, the thickness T1 of the graphene layer 10 may be relatively large from 5 μm to 200 μm. When the heat diffusion sheet 100 is applied to a television including an organic light emitting device (OLED), it may serve to protect the organic light emitting layer of the organic light emitting device together with a heat diffusion function.

In this embodiment, the thickness (T1) of the graphene layer 10 may be larger than the elastic material layer 20, the resin layer 30 and the adhesive layer 40. This is because the graphene layer 10 is a layer that greatly contributes to heat diffusion, so that the thicker the graphene layer 10, the better the heat diffusion characteristics.

However, the present invention is not limited to the above, and the thickness T1 of the graphene layer 10 may have various values.

The elastic material layer 20 formed on one surface (the upper surface of the drawing) of the graphene layer 10 may include an elastic material 22 having elasticity. Accordingly, the graphene layer 10 may be protected by having high durability, scratch resistance, and the like. As the elastic material 22, various materials may be used, for example, rubber.

Here, the elastic material 22 may include ethylene-propylene-diene rubber (EPDM) among rubber. Ethylene-propylene-diene rubber is a synthetic rubber composed of ethylene, propylene, and non-conjugated diene that provides unsaturation across the side chains of a fully saturated main chain. It is excellent in scratch resistance, etc. due to its elasticity. It has excellent properties, weather resistance, durability, and so on.

In addition, the elastic material layer 20 may further include a heat dissipation material 24 distributed in the elastic material 22. The heat dissipation material 24 may include various materials capable of improving heat dissipation properties. For example, as the heat dissipation material 24, a carbon material including graphene, carbon nanotubes, and graphite may be used. The carbon material has excellent heat transfer efficiency because the lattice of carbon atoms is uniformly located.

Here, when the heat dissipation material 24 includes graphene, the width (or the diameter or the length of the long side) of the heat dissipation material 24 may be 1 μm to 20 μm, and the thickness may be 1 nm to 100 nm. If the width of the heat dissipation material 24 is less than 1 μm and the thickness is less than 1 nm, the heat dissipation material 24 may not be properly dispersed in the elastic material 22. When the width of the heat dissipation material 24 exceeds 20 μm and the thickness exceeds 100 nm, the specific surface area of the heat dissipation material 24 may be small, so that heat dissipation properties may not be excellent. At this time, the case of graphene has been described as an example, even if the heat dissipation material 24 is a different material, it may have a width and thickness in the above-described range. Alternatively, the size of the heat dissipation material 24 may be variously modified depending on the material of the heat dissipation material 24. That is, the present invention is not limited to the size of the heat dissipation material 24.

In addition, the elastic material layer 20 may optionally further include a dispersant, an additive, and the like.

At this time, the elastic material layer 20 may include the elastic material 22 in the same amount as the heat dissipation material 24, or may include a larger amount thereof. Thereby, the graphene layer 10 by the elastic material 22 can be effectively protected.

For example, with respect to 100 parts by weight of the entire elastic material layer 20, the elastic material 22 may be included by 50 to 95 parts by weight, and the heat dissipation material 24 may be included by 5 to 50 parts by weight. If the elastic material 22 is less than 50 parts by weight or the heat-radiating material 24 exceeds 50 parts by weight, the amount of the elastic material 50 may not be sufficient to make it difficult to sufficiently protect the graphene layer 10 and the heat-radiating material ( 24) may occur, such as the blowing phenomenon of the powder. If the elastic material 22 exceeds 95 parts by weight or the heat dissipation material 24 is less than 5 parts by weight, the amount of the heat dissipation material 24 may be small, thereby limiting heat dissipation properties. The dispersant may be included in a minimum amount for dispersion (for example, 1 part by weight or less based on 100 parts by weight). However, the present invention is not limited to this, and the elastic material layer 20 is composed of various materials and may have various compositions.

The elastic material layer 20 may be formed by coating the graphene layer 10 with a coating material obtained by mixing the above-described elastic material 22, heat dissipation material 24, and dispersant. Accordingly, the elastic material layer 20 may be formed in contact with the graphene layer 10. Therefore, a separate adhesive layer or the like is not formed between the elastic material layer 20 and the graphene layer 10, so that the thickness of the heat diffusion sheet 100 can be minimized. The elastic material layer 20 includes an elastic material 22 and is located on one surface of the heat diffusion sheet 100 (ie, an external surface of an electronic device, etc. to which the heat diffusion sheet 100 is attached) to external shock and heat. It is possible to effectively prevent damage, deformation, and the like due to deformation and scratches. Thereby, it can have excellent durability. In addition, the elastic material layer 20 may include a heat dissipation material 24 so that the heat diffusion sheet 100 has an excellent heat dissipation effect.

For example, the thickness T2 of the elastic material layer 20 according to the present embodiment may be 5 μm to 200 μm. When the thickness T2 of the elastic material layer 20 is less than 5 μm, the elastic material layer 20 may be torn or powdered in various processes, and it may be difficult to sufficiently protect the graphene layer 10. When the thickness T2 of the elastic material layer 20 exceeds 200 μm, thinning of the heat diffusion sheet 100 may be difficult.

At this time, the thickness T2 of the elastic material layer 20 may vary depending on the application field of the heat diffusion sheet 100. For example, when the heat diffusion sheet 100 is applied to a mobile phone or the like, the thickness T2 of the elastic material layer 20 may be 5 μm to 150 μm (eg, 5 μm to 100 μm). As another example, when the heat diffusion sheet 100 is applied to a large product such as a television, the thickness T2 of the elastic material layer 20 may be relatively large from 5 μm to 200 μm.

The resin layer 30 may be located on the other surface of the graphene layer 10. The resin layer 30 may include a material having excellent heat dissipation properties while being able to remove the defect D of the graphene layer 10. In addition, the resin layer 30 may be formed of a material that can be directly formed on the graphene layer 10 or the support layer 42 by coating or the like. Accordingly, the resin layer 30 may include a thermosetting resin 32 and a heat dissipation material 34. That is, the heat dissipation characteristics can be improved by the heat dissipation material 34 while removing the defect D of the graphene layer 10 by the thermosetting resin 32.

As the thermosetting resin 32, various known thermosetting resins and the like can be used. As an example, the thermosetting resin 32 may be an epoxy resin or a melamine resin. As described above, when the resin layer 30 includes the thermosetting resin 32, the resin layer on the graphene layer 10 is cured by curing the thermosetting resin 32 while the resin layer 30 is in contact with the graphene layer 10. 30 can be formed. That is, the surface of the graphene layer 10 may be easily formed with a defect D in which carbon atoms are not partially located. When the resin layer 30 including the thermosetting resin 32 is placed on the graphene layer 10, The thermosetting resin fills the defect (D) of the graphene layer 10 by the fluidity of the thermosetting resin before curing. When the thermosetting resin 32 is cured by curing in this state, the resin layer 30 is formed with the resin layer 30 all filled with defects D of the graphene layer 10. As a result, since the defect D of the graphene layer 10 is removed, a problem of deterioration of heat dissipation characteristics that may be caused by the defect D can be solved.

In addition, the heat dissipation material 34 included in the resin layer 30 may include various materials capable of improving heat dissipation properties. For example, as the heat dissipation material 34, a carbon material including graphene, carbon nanotubes, and graphite may be used. The carbon material has excellent heat transfer efficiency because the lattice of carbon atoms is uniformly located.

Here, when the heat dissipation material 34 includes graphene, the width of the heat dissipation material 34 may be 1 μm to 20 μm, and the thickness may be 1 nm to 100 nm. If the width of the heat dissipation material 34 is less than 1 μm and the thickness is less than 1 nm, the heat dissipation material 34 may not be properly dispersed in the thermosetting resin 32. When the width of the heat dissipation material 34 exceeds 20 μm and the thickness exceeds 100 nm, the specific surface area of the heat dissipation material 34 may be small, so that heat dissipation properties may not be excellent. At this time, the case of graphene has been described as an example, but the heat dissipation material 34 may have a width and thickness within the above-mentioned range even if it is another material. Alternatively, the size of the heat dissipation material 34 may be variously modified according to the constituent materials of the heat dissipation material 34. That is, the present invention is not limited to the size of the heat dissipation material 34.

In addition, the resin layer 30 may optionally further include a dispersant, an additive, and the like.

At this time, with respect to 100 parts by weight, the heat-curable resin 32 may be included by 40 to 95 parts by weight, and the heat dissipation material 34 may be included by 5 to 60 parts by weight. When the heat-curable resin 32 is less than 40 parts by weight or the heat dissipation material 34 exceeds 60 parts by weight, bonding characteristics between the graphene layer 10 and the adhesive part 40 may be deteriorated. When the heat-curable resin 32 exceeds 95 parts by weight or the heat-dissipating material 34 is less than 5 parts by weight, the amount of the heat-dissipating material 34 may be small, thereby limiting heat dissipation properties and the amount of the heat-curable resin 32 There may be many, uncured. The dispersant may be included in a minimum amount for dispersion (for example, 1 part by weight or less based on 100 parts by weight). However, the present invention is not limited to this, and the resin layer 30 is composed of various materials and may have various compositions.

By removing the defect (D) of the graphene layer 10 by the heat-curable resin 32 of the resin layer 30, and improve the heat dissipation properties by the heat dissipation material 34, the heat diffusion sheet 100 The heat dissipation characteristics of can be improved to the maximum. The resin layer 30 may be directly formed on the graphene layer 10 by coating, or it may be formed on the support layer 42 and cured while being in contact with the graphene layer 10.

For example, the thickness T3 of the resin layer 30 according to the present embodiment may be 5 μm to 200 μm. When the thickness T3 of the resin layer 30 is less than 5 μm, adhesive properties between the graphene layer 10 and the adhesive portion 40 may be deteriorated. When the thickness T3 of the resin layer 30 exceeds 200 μm, thinning of the heat diffusion sheet 100 may be difficult.

At this time, the thickness (T3) of the resin layer 30 may vary depending on the application field of the heat diffusion sheet 100. For example, when the heat diffusion sheet 100 is applied to a mobile phone or the like, the thickness T3 of the resin layer 30 may be 5 μm to 100 μm. As another example, when the heat diffusion sheet 100 is applied to a large product such as a television, the thickness T3 of the resin layer 30 may be relatively large from 5 μm to 200 μm.

An adhesive portion 40 for attachment to an electronic device may be positioned on the resin layer 30. For example, in this embodiment, the adhesive portion 40 may include a support layer 42 formed on the resin layer 30 and an adhesive layer 44 formed on the support layer 42.

The support layer 42 serves to stably support the adhesive layer 44. For example, the support layer 42 may have a shape of a sheet, a film, or the like, including polyethylene phthalate (PET), so that the resin layer 30 and the adhesive layer 44 are stably formed. However, the present invention is not limited to this, and the support layer 42 may have various structures including various materials.

The adhesive layer 44 formed on the support layer 42 is a layer that allows the heat diffusion sheet 100 to be attached to the electronic device. Various materials may be used as the adhesive layer 44, for example, a pressure sensitive adhesive (PSA) may be used. When a pressure-sensitive adhesive is used as the adhesive layer 44, the heat diffusion sheet 100 and the adhesive layer 44 can be easily attached by applying pressure while the adhesive layer 44 is located in the electronic device.

In this embodiment, it is illustrated that the adhesive portion 40 including the resin layer 30, the support layer 42 and the adhesive layer 44 is formed on the other surface of the graphene layer 10. Thereby, the defect layer (D) of the graphene layer 10 is removed and the adhesive layer 44 between the resin layer 30 and the electronic device, which improves heat dissipation properties, is formed integrally with the support layer 42 to form a heat diffusion sheet 100 ) Can simplify the structure and simplify the manufacturing process. However, the present invention is not limited to this, and it is also possible that the support layer 42 and the adhesive layer 44 are not provided. Various other modifications are possible.

The thicknesses T4 and T5 of the support layer 42 and the adhesive layer 44 may vary, and the present invention is not limited thereto.

The heat diffusion sheet 100 having the above-described structure is attached to components of various electronic devices (for example, a display device) to effectively dissipate heat from the electronic devices. At this time, the heat diffusion sheet 100 according to the present embodiment includes a graphene layer 10 having excellent heat diffusion characteristics, and an elastic material layer 20 having excellent durability and heat dissipation characteristics on one surface of the graphene layer 10 ) Is formed, and the resin layer 30 having excellent heat dissipation properties is formed by removing the defect D of the graphene layer 10 on the other surface of the graphene layer 10. Accordingly, the heat diffusion sheet 100 may have excellent durability and heat dissipation characteristics while having a simple structure and a small thickness. In addition, the heat-diffusing sheet 100 has flexible characteristics and can be applied to various electronic products.

For example, the heat diffusion sheet 100 may have a thickness of 15 μm to 600 μm. For example, when the heat diffusion sheet 100 is applied to a mobile phone or the like, it may have a thickness of 15 μm to 50 μm (for example, a thickness of 15 μm to 20 μm). However, the present invention is not limited to this.

On the other hand, in the conventional heat diffusion sheet, an adhesive layer and a polyethylene terephthalate (PET) layer were laminated on one surface of the graphite layer, and a structure of an adhesive layer-PET layer-adhesive layer was laminated on the other surface. Graphite constituting the graphite layer is not an ideal structure, so there are many defects, and the adhesive layer or the like is not suitable for removing defects in the graphite layer. As a result, the heat diffusion characteristics are not excellent. Accordingly, the thickness of the heat-diffusion sheet must be thickened to compensate for the heat-diffusion characteristics, so it can be applied to electronic devices and occupy a large volume. In addition, there are limitations in reducing the thickness of the heat diffusion sheet because a plurality of adhesive layers are included. In addition, there is a problem in that the appearance of the heat-diffusion sheet is deformed or damaged due to the low heat resistance and scratch resistance of the PET layer.

An example of the method of manufacturing the above-described heat diffusion sheet 100 will be described in detail with reference to FIGS. 2A to 2E. Parts already described in the above description are omitted, and only different parts will be described in detail.

2A to 2E are cross-sectional views illustrating a method of manufacturing a heat diffusion sheet 100 according to an embodiment of the present invention.

As shown in FIG. 2A, the graphene layer 10 is prepared.

Subsequently, as shown in FIG. 2B, an elastic material layer 20 is formed on one surface of the graphene layer 10. More specifically, the elastic material layer 20 may be formed by coating the coating material on which the elastic material 22, the heat dissipation material 24, the dispersant, and the additive are mixed on one surface of the graphene layer 10. . As a coating method, various methods such as bar coating, die coating, gravure coating, and comma coating can be used. Drying and / or heat treatment after coating may further be performed.

Subsequently, as illustrated in FIG. 2C, a resin forming layer 30a is formed on the other surface of the graphene layer 10. More specifically, the resin-forming layer 30a may be formed by coating the coating material on which the heat-curable resin 32a, the heat dissipation material 34, the dispersant, and the additive are mixed on the other surface of the graphene layer 10. have. Since the resin forming layer 30a includes a heat-curable resin 32a that is not cured, it has fluidity, and thus can be easily coated on the graphene layer 10. As a coating method, various methods such as bar coating, die coating, gravure coating, and comma coating can be used.

Thus, by forming the resin forming layer 30a on the other surface of the graphene layer 10, defects located on the surface of the graphene layer 10 can be effectively removed.

Subsequently, as illustrated in FIG. 2D, the adhesive portion 40 including the support layer 42 and the adhesive layer 44 is positioned on the resin layer 30. At this time, the support layer 42 may be positioned to be located on the resin layer 30 side and the adhesive layer 44 to be located on the outer surface side.

In this embodiment, it was illustrated that the resin forming layer 30a is formed on the graphene layer 10, and the adhesive portion 40 including the support layer 42 and the adhesive layer 44 is positioned on the resin forming layer 30a. However, the present invention is not limited to this. Accordingly, the resin forming layer 30a is formed on one surface of the support layer 42, the adhesive layer 44 is formed on the other surface of the support layer 42, and then the resin forming layer 30a is positioned to contact the graphene layer 10. It might be.

Subsequently, as shown in FIG. 2E, the heat curable resin 32a is thermally cured by heating to form a resin layer 30 attached to the graphene layer 10 and the support layer 42. The heat curing time, temperature, and the like may vary depending on materials such as a resin layer 30, a support layer 42, and an adhesive portion 36 including the heat-curable resin 32 constituting the heat diffusion sheet 100. As an example, the thermal curing temperature may be 60 ° C to 200 ° C, and the curing time may be 5 minutes to 25 minutes. If the thermal curing temperature is less than 60 ° C or the curing time is less than 5 minutes, curing may not occur well, and if the thermal curing temperature exceeds 200 ° C or the curing time exceeds 25 minutes, the heat diffusion sheet 100 may be bent. have. The thermal curing temperature may be 70 ° C to 150 ° C so as to improve curing properties and minimize bending of the heat diffusion sheet 100. However, the present invention is not limited to this, and various modifications are possible.

As described above, in this embodiment, the elastic material layer 20 and the resin layer 30 are formed by a method such as coating to simplify the layered structure of the heat diffusion sheet 100 to simplify the thickness of the heat diffusion sheet 100. It can be minimized and can simplify the manufacturing process of the heat diffusion sheet 100.

Hereinafter, a heat diffusion sheet according to another embodiment of the present invention will be described in detail with reference to the accompanying drawings. The detailed description of parts described in the above-described embodiment will be omitted, and only different parts will be described in detail.

3 is a cross-sectional view showing a heat diffusion sheet according to another embodiment of the present invention.

Referring to FIG. 3, the heat diffusion sheet 100a according to the present embodiment does not include the resin layer 30 unlike the embodiment of FIG. 1. That is, the elastic material layer 20 is positioned on one surface of the graphene layer 10, and the adhesive portion 40 is positioned on the other surface. At this time, the adhesive portion 40 may include first and second adhesive layers 44a and 44b formed on both sides of the support layer 44 with the support layer 44 interposed therebetween. Then, the adhesive portion 40 can be easily attached to the graphene layer 10 by the first adhesive layer 44a, and the heat diffusion sheet 100a can be easily attached to the electronic device by the second adhesive layer 44b. . As described above, when the graphene layer 10 and the adhesive portion 40 are attached using the first adhesive layer 44a, processes required for coating and thermal curing of the resin layer 30 can be omitted, thereby simplifying the manufacturing process. have.

Since the first and second adhesive layers 44a and 44b have the same or extremely similar configuration to the adhesive layer 44 of FIG. 1, detailed descriptions are omitted.

4 is a cross-sectional view showing a heat diffusion sheet according to another embodiment of the present invention.

Referring to FIG. 4, the heat diffusion sheet 100b according to the present embodiment does not include the elastic material layer 20, unlike the embodiment of FIG. 1. That is, the resin layer 30 or the like is located only on one surface of the graphene layer 10 (that is, the lower surface of the drawing) to effectively remove defects of the graphene layer 10. Thereby, the laminated structure of the heat diffusion sheet 100a can be minimized and the thickness of the heat diffusion sheet 100a can be minimized.

5 is a cross-sectional view showing a heat diffusion sheet according to another embodiment of the present invention.

5, in the heat diffusion sheet 100c according to the present embodiment, the first and second resin layers 302 and 304 are located on both sides of the graphene layer 10, respectively, and the second resin layer 304 The adhesive portion 40 is located on the top. Since the first and second resin layers 302 and 304 have the same or extremely similar configuration to the resin layer 30 of FIG. 1, detailed descriptions are omitted. As described above, defects of the graphene layer 10 can be effectively removed by placing the first and second resin layers 302 and 304 on both sides of the graphene layer 10.

In this case, although FIG. 5 illustrates that a separate layer is not provided on the first resin layer 302, the present invention is not limited thereto. Accordingly, as illustrated in FIG. 6, the elastic material layer 20 illustrated in the embodiment of FIG. 1 may be additionally positioned on the first resin layer 302.

Hereinafter, a heat diffusion sheet according to an embodiment of the present invention will be described in more detail through experimental examples. Experimental examples are only for illustrative purposes, and the present invention is not limited thereto.

Manufacturing example  One

On the front surface of the 15 μm thick graphene layer, a coating material containing graphene and EPDM was coated to form an elastic material layer to a thickness of 10 μm to prepare a heat diffusion sheet.

Manufacturing example  2

On the back of the graphene layer, a resin-forming layer containing a heat-curable resin and graphene is formed to a thickness of 10 μm, and then a support layer composed of PET and an adhesive layer composed of PSA are placed on the resin-forming layer side, and then thermally cured at 80 ° C. for 10 minutes A resin layer was formed to prepare a heat diffusion sheet. Accordingly, the resin layer, the support layer, and the adhesive layer were sequentially located on the other surface of the graphene layer.

Manufacturing example  3

A coating material containing graphene and EPDM was coated on the front surface of the 15 μm-thick graphene layer to form an elastic material layer to a thickness of 10 μm. A heat diffusion sheet was prepared by placing an adhesive portion including a PSA layer-PET layer-PSA layer on the back side of the graphene layer.

Comparative example  One

A heat-diffusion sheet was prepared by attaching PET through an adhesive layer on the front surface of a 50 μm-thick graphite layer.

Comparative example  2

A heat-diffusion sheet was prepared by placing an adhesive portion in which an adhesive layer composed of PSA, a support layer composed of PET, and an adhesive layer composed of PSA were sequentially located on the back surface of the graphite layer of 50 μm thickness.

Comparative example  3

A heat-diffusion sheet was prepared by attaching PET through an adhesive layer on the front surface of a 50 μm-thick graphite layer. A heat diffusion sheet was prepared by placing an adhesive portion including a PSA layer-PET layer-PSA layer on the back side of the graphene layer.

Hot spot in the stainless steel (SUS) itself and points located at regular intervals between the hot spot and the rotor in a state where the heat diffusion sheets according to Example 1 and Comparative Example 1 located at regular intervals therefrom are attached to the stainless steel The temperature of the was measured with an infrared thermometer and the results are shown in Table 1 in units of ℃. At this time, the first position is spaced apart by a first distance (L) from the hot spot, the second position is spaced twice as much (2L) as the first distance from the hot spot, and the third position is 3 of the first distance from the hot spot. Spaced apart by 3L. The same experiment was conducted for Production Example 2 and Comparative Example 2, and the results are shown in Table 2. The same experiment was performed for Production Example 3 and Comparative Example 3, and the results are shown in Table 3.

location Hot spot One 2 3 4 5 6 7 8 SUS 61 58 49 41 36 32 30 27 26 Example 1 50 48 41 36 33 31 28 27 26 Comparative Example 1 53 50 44 39 35 32 29 28 26

location Hot spot One 2 3 4 5 6 7 8 SUS 61 58 49 41 36 32 30 27 26 Example 2 50 48 43 38 34 32 30 28 27 Comparative Example 2 52 50 43 39 35 33 30 28 27

location Hot spot One 2 3 4 5 6 7 8 SUS 61 58 49 41 36 32 30 27 26 Example 3 50 48 41 36 33 31 28 27 26 Comparative Example 3 53 50 44 39 35 32 29 28 26

Referring to Table 1, in SUS itself, the temperature at the hot spot is 61 ° C., and in Comparative Example 1, the temperature at the hot spot is 53 ° C., whereas in the heat diffusion sheet according to Example 1, the temperature at the hot spot is 50 ° C. It can be seen that. That is, it can be seen that by attaching the heat diffusion sheet according to Example 1, the heat at the hot spot can be quickly diffused to effectively lower the temperature at the hot spot. At this time, it can be seen that the temperature at the hot spot can be lowered by 3 ° C. in Example 1 having a graphene layer having a thinner thickness than Comparative Example 1 in which the thickness of the graphite layer is 50 μm.

Referring to Table 2, in SUS itself, the temperature at the hot spot is 61 ° C., and in Comparative Example 2, the temperature at the hot spot is 52 ° C., whereas the heat diffusion sheet according to Example 2 has a temperature at the hot spot of 50 ° C. It can be seen that. That is, it can be seen that by attaching the heat diffusion sheet according to Example 2, the heat at the hot spot can be quickly diffused to effectively lower the temperature at the hot spot. At this time, it can be seen that the temperature at the hot spot can be lowered by 2 ° C. in Example 2 with a thin thickness compared to Comparative Example 2 with a thick thickness.

Referring to Table 3, in SUS itself, the temperature at the hot spot is 61 ° C., and in Comparative Example 3, the temperature at the hot spot is 53 ° C., whereas the heat diffusion sheet according to Example 3 has a temperature at the hot spot of 50 ° C. It can be seen that. That is, it can be seen that by attaching the heat diffusion sheet according to Example 3, the heat at the hot spot can be quickly diffused to effectively lower the temperature at the hot spot. At this time, it can be seen that the temperature at the hot spot can be lowered by 3 ° C. in Example 3 with a thin thickness compared to Comparative Example 3 with a thick thickness.

Thus, according to Examples 1 to 3, it can be seen that it has excellent heat diffusion properties while having a thin thickness.

Features, structures, effects, and the like as described above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, and the like exemplified in each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

100: heat diffusion sheet
10: graphene layer
20: elastic material layer
30: resin layer
40: adhesive
42: support layer
44: adhesive layer

Claims (20)

A graphene layer comprising graphene; And
An elastic material layer located on one surface of the graphene layer and including an elastic material having elasticity and a first heat dissipation material composed of graphene; And
Located on the other side of the graphene layer, a resin layer comprising a heat-curable resin, and a second heat dissipation material composed of graphene
Including,
The elastic material layer is formed in contact with the graphene layer,
The thickness of the graphene layer is greater than the thickness of the elastic material layer and greater than the thickness of the resin layer,
With respect to the total 100 parts by weight of the elastic material layer, the elastic material is contained by 50 to 95 parts by weight, the first heat dissipation material by 5 to 50 parts by weight,
With respect to the total 100 parts by weight of the resin layer, the thermosetting resin is contained by 40 to 95 parts by weight, the second heat dissipation material is included by 5 to 60 parts by weight,
The width of the first heat radiation material is 1㎛ to 20㎛, the thickness is 1nm to 100nm,
The heat spreading sheet having a width of 1 μm to 20 μm and a thickness of 1 nm to 100 nm of the second heat dissipation material. According to claim 1,
A heat diffusion sheet in which the elastic material of the elastic material layer is made of rubber. According to claim 2,
The elastic material is an ethylene-propylene-diene rubber (ethylene-propylene-diene rubber, EPDM) heat diffusion sheet comprising.

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