KR20130105021A - Heat radiating sheet - Google Patents

Abstract

PURPOSE: A heat radiation sheet improves re-workability by including an optimized adhesive layer. CONSTITUTION: A first layer (110) includes thermally conductive particles. The first layer includes layer forming materials. A second layer (120) includes the thermally conductive particles and an adhesive. A base material (130) is placed between the first layer and the second layer. The first layer is composed of a paint layer.

Description

Heat Resistant Sheet {HEAT RADIATING SHEET}

The present invention relates to a heat dissipation sheet, and more particularly, to a heat dissipation sheet having excellent heat transfer and thermal diffusion performance in a vertical direction and a horizontal direction and excellent reworkability.

In recent years, electronic devices are becoming more and more compact as they become lighter and shorter and more versatile, and thus, measures to solve heat emission problems are required due to an increase in heat density. In addition, the release of heat is important because it is closely related to the reliability and lifetime of the device. Accordingly, various heat dissipation materials are being developed, and are marketed in the form of heat dissipation pads, heat dissipation sheets, and heat dissipation paints to assist or replace heat dissipation devices such as heat dissipation fans, heat dissipation fins, and heat pipes.

Among them, the heat-radiating sheet is manufactured in the form of a graphite compression sheet, a polymer-ceramic composite sheet, a multilayer coating metal thin film sheet, etc. The graphite compression sheet is excellent in horizontal thermal conductivity, The polymer-ceramic composite sheet has a limited thermal conductivity, and the multilayered coating metal thin sheet has a low horizontal thermal diffusivity.

Therefore, there is a need for a heat radiation sheet excellent in heat transfer and thermal diffusion performance in the vertical and horizontal directions, and excellent in reworkability.

Accordingly, it is an object of the present invention to provide a heat-radiating sheet including a pressure-sensitive adhesive layer having excellent heat transfer and thermal diffusion performance in a vertical direction and a horizontal direction, and having excellent adhesiveness.

According to the above object, the present invention provides a method of manufacturing a semiconductor device, comprising: (i) a first layer comprising thermally conductive particles and a layer forming material; (ii) a second layer which is an adhesive layer comprising thermally conductive particles and a pressure-sensitive adhesive; And (iii) a substrate positioned between the first layer and the second layer.

The heat-radiating sheet according to the present invention is excellent in re-workability, including an adhesive layer having excellent heat transfer and thermal diffusivity in the vertical and horizontal directions and having optimized adhesiveness.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view schematically showing the structure of a heat-radiating sheet according to the present invention. FIG.
2 is a view schematically showing the structure of another heat-radiating sheet according to the present invention.

Hereinafter, the present invention will be described in more detail.

The heat-radiating sheet of the present invention comprises (i) a first layer comprising thermally conductive particles and a layer-forming material; (ii) a second layer which is an adhesive layer comprising thermally conductive particles and a pressure-sensitive adhesive; And (iii) a substrate positioned between the first layer and the second layer.

That is, the heat-radiating sheet according to the present invention is a heat-radiating sheet comprising a first layer including thermally conductive particles and a layer-forming material formed on one surface of the substrate having a film form in a plane, Layer may be formed on the first layer.

The first layer includes thermally conductive particles and a layer forming material. The layer forming material may be an adhesive layer including an adhesive, a pressure sensitive adhesive layer containing a pressure sensitive adhesive, or a paint layer containing a resin.

The pressure-sensitive adhesive and the adhesive are distinguished depending on whether they are cured after the pressure-sensitive adhesive or the pressure-sensitive adhesive. Examples of the pressure-sensitive adhesive include those of acrylic type, urethane type, epoxy type, silicone type, . In the case where the first layer is a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive as a layer-forming material, the pressure-sensitive adhesive included in the first layer and the pressure-sensitive adhesive included in the second layer May be the same or different.

When the first layer is a coating layer containing a resin as the layer forming material, examples of the resin include at least one resin selected from the group consisting of an acrylic resin, a urethane resin, and an epoxy resin.

When the first layer is a paint layer, the first layer may further include a curing agent in addition to the resin. Examples of the curing agent include an organic peroxide type, an isocyanate type, an azo type, an amine type, an amidazole type, an acid anhydride type, a Lewis acid type and a formaldehyde type compound and are not particularly limited as they are commonly used in sugar buds.

The first and second layers include thermally conductive particles. The thermally conductive particles have a thermal conductivity of 1 W / mK or more. Examples thereof include carbon black, carbon nanotubes, carbon nanofibers, graphenes, metal oxides, Metal nitrides, and metal particles. These thermally conductive particles may be used alone or in combination of two or more. The thermally conductive particles included in the first layer and the thermally conductive particles included in the second layer may be the same or different.

Examples of the metal oxide include magnesium oxide, aluminum oxide, silicon oxide, zinc oxide and zirconium oxide. Examples of the metal nitride include boron nitride, aluminum nitride, and silicon nitride. Examples of the metal particles include silver , Aluminum or zinc.

As the thermally conductive particles, carbon nanotubes, magnesium oxide, or boron nitride may be particularly preferably used. In this case, when the carbon nanotubes are used as the thermally conductive particles, the single-walled or multi-walled carbon nanotubes And preferably an inorganic acid such as hydrochloric acid, sulfuric acid or nitric acid, or an organic acid such as citric acid, succinic acid or acetic acid may be used.

The thermally conductive particles act as a heat conduction medium in the first layer or the second layer to exert heat transfer and thermal diffusion effects in the vertical direction and the horizontal direction of the heat radiation sheet.

The thermally conductive particles may be contained in an amount of 5 to 80 parts by weight based on 100 parts by weight of the first layer or the second layer, respectively. When the thermally conductive particles are contained in less than 5 parts by weight in each of the first layer and the second layer, a desired heat conduction effect is not exhibited, and when the thermally conductive particles are contained in an amount exceeding 80 parts by weight, flexibility of the heat- So that breakage or breakage occurs during bending, which is not preferable.

The thermally conductive particles preferably have an average particle diameter of 1 to 30 μm, more preferably 5 to 15 μm. When the average particle diameter of the thermally conductive particles is less than 1 占 퐉, dispersion and thermal conductivity characteristics may be lowered, and when the average particle diameter exceeds 30 占 퐉, Can not do it.

The first layer can be formed by applying a composition obtained by mixing the thermally conductive particles with a layer forming material onto a substrate. The thickness of the first layer may be between 5 and 80 탆, preferably between 10 and 25 탆, and the first layer may contain thermally conductive particles in an amount of 5 to 80 parts by weight based on 100 parts by weight of the first layer 8 to 50 parts by weight may be included.

When the first layer is an adhesive layer containing an adhesive as a layer forming material, a plastic film may be further laminated on the exposed surface of the first layer. When a plastic film is laminated on the adhesive layer, a horizontal thermal diffusion function can be further given.

The plastic film may be made of polyethylene (PE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate Or polyimide (PI), and more preferably polypropylene (PP), polystyrene (PS), or polyethylene terephthalate (PET).

The thickness of the plastic film may be 5 to 200 mu m, preferably 10 to 100 mu m.

Further, the second layer can be formed by mixing the thermally conductive particles with a pressure-sensitive adhesive and applying the mixture onto a substrate. The thickness of the second layer may be between 5 and 80 탆, and preferably between 10 and 25 탆. The second layer may contain 5 to 80 parts by weight, preferably 8 to 50 parts by weight of the thermally conductive particles based on 100 parts by weight of the second layer.

Examples of the application method include die coating, gravure coating, microgravure coating, comma coating, roll coating, dip coating, spray coating and the like, preferably gravure coating or comma coating.

The substrate may be a metal thin film, a metal mesh, a polymer mesh or a fiber mesh. Examples of the metal thin film include an aluminum thin film, a copper thin film and a nickel thin film. Examples of the metal mesh include aluminum mesh, copper mesh, Or an iron mesh. Examples of the polymer mesh include polyester meshes, polypropylene meshes, and polyurethane meshes. Examples of the fiber meshes include glass fiber meshes, acrylic fiber meshes, or nylon fiber meshes. . Among these, an aluminum thin film, a copper thin film, or a glass fiber mesh can be preferably used.

The thickness of the substrate may be from 5 to 300 탆, and preferably from 10 to 200 탆.

The heat radiation sheet according to the present invention can improve the heat transfer and thermal diffusion performance in the vertical direction and the horizontal direction by including the first layer and the second layer having the form of a thin sheet and including the thermally conductive particles as a heat conduction medium, Since the second layer is made of an adhesive layer, it can be attached and detached one or more times when attached to an electronic device or the like, and the reworkability can be improved.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a preferred heat-radiating sheet according to the present invention will be described in detail with reference to the drawings.

Fig. 1 shows a preferred example of the heat-radiating sheet according to the present invention. Referring to FIG. 1, a heat-radiating sheet 100 according to the present invention includes a first layer 110 as an adhesive layer including thermally conductive particles and a pressure-sensitive adhesive, a second layer 120 as an adhesive layer including thermally conductive particles and a pressure- And a substrate 130 positioned between the first layer 110 and the second layer 120. As shown in FIG.

2 shows another preferred embodiment of the heat-radiating sheet according to the present invention. 2, a heat-radiating sheet 200 according to the present invention includes a first layer 210 as an adhesive layer including thermally conductive particles and an adhesive, a second layer 220 as an adhesive layer including thermally conductive particles and a pressure- A substrate 230 positioned between the first layer 210 and the second layer 220 and a plastic film 240 bonded to the first layer 210. [ When a plastic film is laminated on the first layer as the adhesive layer as described above, it is more preferable to further provide a thermal diffusion function in the horizontal direction.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

Example  One

25 parts by weight of carbon nanotubes having a particle size of 10 占 퐉 as a thermally conductive particle, 65 parts by weight of an acrylic adhesive (WA770, manufactured by Uin Chemtech Co., Ltd.) and 10 parts by weight of ethyl acetate was coated on one surface of a 100 탆 thick aluminum thin film with a comma coating Method to form a first layer, and a 12 占 퐉 thick polyethylene terephthalate (PET) film was laminated thereon. Subsequently, a composition prepared by mixing 25 parts by weight of carbon nanotubes having a particle size of 10 mu m, 65 parts by weight of an acrylic pressure-sensitive adhesive (TT-1500, manufactured by TT Chemical Co.) and 10 parts by weight of ethyl acetate was applied to the other surface of the aluminum thin film by a comma coating method (MR-G03, manufactured by SYC Corporation) having a thickness of 12 占 퐉 and made of silicon was attached to protect the adhesive layer to prepare a heat-radiating sheet.

Example  2

(TT-1550, manufactured by TT Chemical Co., Ltd.) instead of the acrylic adhesive in the formation of the first layer, and then the first layer was formed by thermosetting using a comma coating method. 1, a heat-radiating sheet was prepared.

Example  3

A heat-radiating sheet was prepared in the same manner as in Example 1, except that an acrylic pressure-sensitive adhesive (TT-1500, manufactured by TT Chemical Co., Ltd.) was used instead of the acrylic adhesive in the formation of the first layer.

Example  4

A heat radiation sheet was prepared in the same manner as in Example 1, except that the first layer and the second layer were formed by using 25 parts by weight of magnesium oxide having a particle size of 10 占 퐉 in place of the carbon nanotubes as the thermally conductive particles.

Example  5

A heat radiation sheet was prepared in the same manner as in Example 2, except that the first layer and the second layer were formed by using 25 parts by weight of magnesium oxide having a particle size of 10 占 퐉 in place of the carbon nanotubes as the thermally conductive particles.

Example  6

A heat radiation sheet was prepared in the same manner as in Example 3, except that the first layer and the second layer were formed using 25 parts by weight of magnesium oxide having a particle size of 10 mu m instead of the carbon nanotubes as the thermally conductive particles.

Comparative Example  One

A heat-radiating sheet was produced in the same manner as in Example 1, except that the thermally conductive particles were not used in forming the first layer and the second layer.

Comparative Example  2

A heat-radiating sheet was produced in the same manner as in Example 1, except that the first layer was not formed and the thermally conductive particles were not used in forming the second layer.

Comparative Example  3

A heat-radiating sheet was produced in the same manner as in Example 3, except that the thermally conductive particles were not used in forming the first layer and the second layer.

Experimental Example

The heat radiation sheets prepared in Examples 1 to 6 and Comparative Examples 1 to 3 were each cut into a size of 200 X 100 mm ² , and a heat source for generating heat at 80 ° C was attached to one end. After 30 minutes, (Thermocouple; DTM-305, manufactured by TECPEL). Then, the temperature at a point 150 mm away from the heat source on the sheet was measured, the temperature difference (ΔT) with the heat source was recorded, and the electric conductivity was also measured. The above results are shown in Table 1 below.

Heat source temperature (℃) In the seat
Horizontal direction ΔT Electrical conductivity Early 80 ㅡ ㅡ Example 1 58 22 Isolation Example 2 55 24 challenge Example 3 55 23 challenge Example 4 61 24 Isolation Example 5 57 26 Isolation Example 6 58 26 Isolation Comparative Example 1 69 31 Isolation Comparative Example 2 64 33 challenge Comparative Example 3 64 33 challenge

The larger the temperature lowering width of the heat source in Table 1, the better the vertical thermal conduction and the horizontal thermal diffusing performance of the heat-radiating sheet. Since the lowering of the heat source temperature is influenced by the vertical heat conduction performance in Table 1, the larger the temperature lowering width of the heat source is, the better the vertical thermal conduction performance is. The lower the temperature difference in the horizontal direction of the heat spreading sheet, It means excellent.

As can be seen from the above Table 1, the heat radiation sheets of Examples 1 to 6 have a larger temperature lowering width than that of the heat radiation sheets of Comparative Examples 1 to 3, and thus the heat transfer performance is better. In addition, it can be seen that the heat radiation sheets of Examples 1 to 6 are superior to the heat radiation sheets of Comparative Examples 1 to 3 in the horizontal direction because the temperature difference in the horizontal direction is small.

On the other hand, in Examples 1 and 4, it can be seen that the horizontal direction temperature difference is smaller than that in Examples 2 and 3, and 5 and 6, respectively, because the horizontal direction thermal diffusing performance is increased by the upper plastic film layer to be.

As can be seen from Table 1, since the heat-radiating sheet according to the present invention has different electric conduction characteristics, a conductive type or an insulating type can be selected and applied to a target device requiring heat dissipation.

100, 200: heat-radiating sheet
110, 210: first layer
120, 220: Second layer
130, 230: substrate
240: Plastic film

Claims (10)

(i) a first layer comprising thermally conductive particles and a layer forming material;
(ii) a second layer which is an adhesive layer comprising thermally conductive particles and a pressure-sensitive adhesive; And
(iii) a substrate located between the first layer and the second layer
Heat dissipation sheet comprising a.
The method of claim 1,
The said 1st layer is a heat-radiation sheet characterized by the said layer forming material as an adhesive layer containing an adhesive, an adhesive layer containing an adhesive, or a coating layer containing resin.
3. The method of claim 2,
And the first layer is an adhesive layer containing an adhesive as the layer forming material, the heat dissipating sheet further comprising a plastic film laminated to the first layer.
The method of claim 1,
Wherein the thickness of the first layer is 5 to 80 占 퐉, the thickness of the second layer is 5 to 80 占 퐉, and the thickness of the base is 5 to 300 占 퐉.
The method of claim 1,
Wherein the thermally conductive particles are at least one selected from the group consisting of carbon black, carbon nanotubes, carbon nanofibers, graphenes, metal oxides, metal nitrides, and metal particles.
The method of claim 1,
The thermally conductive particles included in the first layer may be included in an amount of 5 to 80 parts by weight based on 100 parts by weight of the first layer and the thermally conductive particles contained in the second layer may be contained in an amount of 5 to 100 parts by weight, 80 parts by weight of the heat-radiating sheet.
The method of claim 1,
The thermally conductive sheets included in the first layer or the second layer each have a mean particle size of 1 to 30 μm.
The method of claim 1,
Wherein the substrate is a metal thin film, a metal mesh, a polymer mesh, or a fiber mesh.
The method of claim 8,
Wherein the metal thin film is an aluminum thin film, a copper thin film, or a nickel thin film, and the metal mesh is an aluminum mesh, a copper mesh, a nickel mesh, or an iron mesh, and the polymer mesh is a polyester mesh, a polypropylene mesh, Wherein the fiber mesh is a glass fiber mesh, an acrylic fiber mesh, or a nylon fiber mesh.
The method of claim 3, wherein
The plastic film may be made of polyethylene (PE), polypropylene (PP), polystyrene (PS), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PI). ≪ / RTI >

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