KR20210060014A - Composite sheet with emi shielding and heat radiation and display apparatus comprising the same - Google Patents

Abstract

The present invention provides a composite sheet for electromagnetic wave shielding and heat dissipation which can implement a uniform heat dissipation effect, and a display device including the same. The composite sheet for electromagnetic wave shielding and heat dissipation comprises: a heat dissipation layer; an electromagnetic wave shielding layer laminated on an upper surface of the heat dissipation layer; and an adhesive layer laminated between the heat dissipation layer and the electromagnetic wave shielding layer, wherein the heat dissipation layer is formed of a first area and a second area disposed on both sides of the first area, and the first area has a laminated structure of a plurality of polyimide-based resin films. The electromagnetic wave shielding layer includes a polyimide-based resin film layer and an electromagnetic wave shielding functional layer disposed on both sides of the polyimide-based resin film layer to be spaced apart from each other.

Description

Composite sheet for electromagnetic wave shielding and heat dissipation, and a display device including the same {COMPOSITE SHEET WITH EMI SHIELDING AND HEAT RADIATION AND DISPLAY APPARATUS COMPRISING THE SAME}

The present invention relates to a composite sheet for electromagnetic wave shielding and heat dissipation, and a display device including the same. More specifically, the present invention can implement electromagnetic wave shielding, heat dissipation effect, good folding property, good folding durability, and reduce the heat difference between the folding and non-folding parts to realize a uniform heat dissipation effect. It relates to a composite sheet for heat dissipation and a display device including the same.

With the recent high performance and lightness of electronic devices, the demand for heat dissipation sheets that can effectively dissipate heat generated from heat sources such as semiconductor components and light emitting parts embedded therein is steadily increasing, and complex functionalization for electromagnetic wave shielding is increasing. Is being demanded.

As the heat dissipation sheet, copper foil, copper foil/graphite laminate, graphite sheet, and the like are used. Copper foil has both heat dissipation characteristics and electromagnetic wave shielding characteristics, but when the thickness increases, flexibility is insufficient, heat conduction in the horizontal direction is less than that of graphite, and due to its high density, there is a limit to weight reduction. In addition, when the thickness exceeds about 50 μm, flexibility is insufficient, and thus it is limited to be applied as a heat dissipating sheet having a complex shape.

In recent years, as portable electronic devices are required to be flexible and thin, there is an increasing demand for flexible physical properties and thinning of heat dissipation sheets and electromagnetic wave shielding sheets, which are essential components used therein. The flexible display device has a structure in which stainless steel (SUS), which is a reinforcing material, is spaced apart from each other to form a folding portion for a folding function and is spaced apart from each other. Heat dissipation sheets (eg, copper foil or copper alloy sheet) stacked on the reinforcing material are also arranged spaced apart from each other by the folding portion. As a result, since the heat dissipation sheet is not disposed in the folding portion, a difference in heat generation is inevitable between the folding portion and the non-folding portion.

Accordingly, there is a need for a composite sheet capable of implementing a heat dissipation function and an electromagnetic wave shielding function, while reducing the above-described heat dissipation difference along with folding properties, thereby realizing a uniform heat dissipation effect throughout the display device.

Background technology of the present invention is disclosed in Korean Patent No. 10-1922938 and the like.

An object of the present invention is to provide a composite sheet for electromagnetic wave shielding and heat dissipation having excellent horizontal thermal conductivity, excellent heat dissipation effect, and excellent electromagnetic wave shielding property.

Another object of the present invention is to provide a composite sheet for electromagnetic wave shielding and heat dissipation having excellent folding properties and/or folding durability.

Another object of the present invention is to provide a composite sheet capable of realizing a uniform heat dissipation effect by reducing the difference in heat generation between a folded portion and a non-folded portion.

The composite sheet for electromagnetic wave shielding and heat dissipation of the present invention includes a heat radiation layer, an electromagnetic wave shield layer laminated on an upper surface of the heat radiation layer, and an adhesive layer laminated between the heat radiation layer and the electromagnetic wave shield layer, the heat radiation layer Consisting of a first region and a second region disposed on both sides of the first region, the first region has a laminated structure of a plurality of polyimide films, and the electromagnetic wave shielding layer is a polyimide resin film layer and And an electromagnetic wave shielding functional layer disposed to be spaced apart from each other on both side surfaces of the polyimide resin film layer.

The display device of the present invention includes a composite sheet for shielding and dissipating electromagnetic waves of the present invention.

The present invention provides a composite sheet for electromagnetic wave shielding and heat dissipation having excellent horizontal thermal conductivity, excellent heat dissipation effect, and excellent electromagnetic wave shielding property.

The present invention provides a composite sheet for electromagnetic wave shielding and heat dissipation excellent in folding and folding durability.

The present invention provides a composite sheet capable of realizing a uniform heat dissipation effect by reducing the difference in heat generation between the folded portion and the non-folded portion.

1 is a cross-sectional view in the thickness direction of a composite sheet according to an embodiment of the present invention.
2 is a top plan view of a second region of a heat dissipation layer in a composite sheet according to an exemplary embodiment of the present invention.
3 is a cross-sectional view in the thickness direction of a composite sheet according to another embodiment of the present invention.
4 is a cross-sectional view in the thickness direction of a composite sheet according to another embodiment of the present invention.
5 is a cross-sectional view in the thickness direction of a composite sheet according to another embodiment of the present invention.
6 shows evaluation results of a folding test in Example 1, Example 22, and Example 23. FIG.
7 is a result of evaluating the thermal diffusivity of Example 1, Example 8, and Example 22. FIG. In FIG. 7, M1, M2, and M3 denote a temperature measurement part of the composite sheet, respectively.

The present invention will be described in detail so that those skilled in the art can easily implement the present invention by the following examples. The present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and the same reference numerals are assigned to the same or similar components throughout the specification. In the drawings, the length, thickness, and the like of each component are illustrated to explain the present invention, and the present invention is not limited to the length, thickness, and the like described in the drawings.

When describing the numerical range in the present specification, "X to Y" means X or more and Y or less (X≤ and ≤Y).

A composite sheet (hereinafter, referred to as "composite sheet") for electromagnetic wave shielding and heat dissipation according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

1 is a cross-sectional view in the thickness direction of a composite sheet according to an embodiment of the present invention.

Referring to FIG. 1, the composite sheet includes a heat dissipation layer 100 and an electromagnetic wave shielding layer 200. An adhesive layer 300 is stacked between the heat radiation layer 100 and the electromagnetic wave shielding layer 200, and the heat radiation layer 100 and the electromagnetic wave shielding layer 200 are adhered to each other by the adhesive layer 300.

In one embodiment, the composite sheet includes at least a structure in which the heat dissipation layer 100, the adhesive layer 300, and the electromagnetic wave shielding layer 200 are sequentially stacked, and the heat dissipation layer 100, the adhesive layer 300, and the electromagnetic wave shielding The layer 200 is integrated. The "integration" means that the heat dissipation layer 100, the adhesive layer 300, and the electromagnetic wave shielding layer 200 are not separated from each other by a physical force, for example, stress and/or tension applied during folding of the composite sheet. do.

The heat dissipation layer 100 includes a first region 110 and respective second regions 120 disposed on both sides of the first region 110. Through this, it is possible to provide a uniform heating effect by reducing the difference in heat generation between the folded portion and the non-folded portion.

In the first region 110, a plurality of polyimide resin films 111 are stacked in the thickness direction of the heat dissipation layer. The electromagnetic wave shielding layer 200 has a structure in which the polyamide-based resin film layer 210 and the electromagnetic wave shielding function layer 220 are segmented from each other. Here, "segmented" means that the electromagnetic wave shielding functional layers 220 are disposed on both sides of the polyimide resin film layer 210 to be spaced apart from each other by a separation distance S21. The laminated structure and segmented structure of the polyimide resin film may offset stress and/or tension received by the electromagnetic wave shielding layer when the composite sheet is folded.

As described above, in the present invention, in the composite sheet, the first region and the second region are provided in the heat dissipation layer, the laminated structure of the polyimide resin film is formed in the first region, and the segmented structure is formed in the electromagnetic wave shielding layer to shield electromagnetic waves. And, while realizing the heat dissipation effect, good folding property, folding durability, and uniform heat dissipation effect between the folding and non-folding parts were realized. In the absence of any of the laminated structure of the polyimide resin film in the first region of the heat dissipation layer 100 or the segmented structure provided with the polyimide resin film layer described above in the electromagnetic wave shielding layer 200, good folding performance Folding durability, heat dissipation effect cannot be realized.

Each layer constituting the composite sheet will be described in detail.

Heat dissipation layer

The heat dissipation layer 100 may support the electromagnetic wave shielding layer 100 and/or various reinforcing materials that may be stacked on the upper surface of the electromagnetic wave shielding layer 100.

The heat dissipation layer 100 has excellent thermal conductivity and provides a heat dissipation function to the composite sheet.

The heat dissipation layer 100 may include a first region 110 and respective second regions 120 disposed on both sides of the first region 110. While the conventional composite sheet is composed of only the second region without the first region for the folding function, the composite sheet of the present invention provides a uniform heat dissipation effect by providing a heat dissipation function to both the folding and non-folding regions.

As shown in FIG. 1, the first region 110 and the second region 120 are adhered to each other by an adhesive layer 300 constituting the first region 110.

The first region 110 may correspond to a folding portion that performs a folding function when the composite sheet is applied to the display device. The second area 111 may correspond to a non-folding portion when the composite sheet is applied to the display device. The criteria for classifying the first region 110 and the second region 120 of the heat dissipation layer 100 will be described in more detail in the electromagnetic wave shielding layer 200 described below.

The first region 110 includes a laminate structure in which two or more polyimide resin films are stacked in the thickness direction of the heat dissipation layer. Through this, it is possible to obtain the effect of reinforcing the durability of the folding part and implementing the folding performance.

1 shows that two polyimide-based resin films are laminated, but the present invention is not limited thereto, and 2 to 20, preferably 2 to 10, polyimide resin films may be laminated.

The ratio of the total thickness of the polyimide resin film to the total thickness of the first region is 25 to 95%, preferably 27.27% to 93.28%, 45% to 80%, more preferably 60% to 71.43%. I can. In the above range, there may be an effect of reinforcing durability of the folding portion and implementing the folding performance.

In the laminated structure of the polyimide resin film in the first region, the separation distance between the polyimide resin films may be 3 μm to 20 μm, preferably 5 μm to 10 μm. In the above range, there may be an effect of reinforcing durability of the folding portion and implementing the folding performance.

The polyimide resin film may be formed by employing a common type known to a person skilled in the art as a polyimide resin. For example, the polyimide-based resin may be prepared by solution polymerization of an aromatic dianhydrad and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative, followed by ring closure dehydration at a high temperature for imidization, but is not limited thereto.

The thickness of each of the polyimide resin films may be 3 μm to 20 μm, preferably 5 μm to 10 μm. In the above range, there may be an effect of reinforcing durability of the folding portion and implementing the folding performance.

The first region 110 may be filled with an adhesive. The adhesive may fix the polyimide resin film and bond the first region and the second region to each other.

In one embodiment, the adhesive may have an elongation of 600% or more, for example 600% to 800%. In the above range, it may help to improve folding properties and folding durability. In the present specification, "elongation" may be measured by the method described in the experimental examples detailed below.

In another embodiment, the adhesive may have a cohesive force of 3.0 kgf/inch or less, for example, 2.0 kgf/inch to 2.5 kgf/inch. In the above range, it may help to improve folding properties and folding durability. In the present specification, "cohesive force" can be measured by the method described in the experimental examples detailed below.

When an adhesive that satisfies both the elongation and cohesiveness described above is used, the folding property of the present invention can be further improved.

The second region 120 may be a layer formed of a conventional material known to be capable of implementing a heat dissipation function. For example, the second region 120 may include a graphite layer.

If the second region 120 is a material known to those skilled in the art to provide a heat dissipation effect, the material is not limited. For example, the second region may include a graphite layer including at least one of pyrolytic graphite and graphitized polyimide. The pyrolytic graphite refers to high-purity graphite having high thermal conductivity and electrical conductivity, is used at high temperatures, is manufactured by a vapor deposition method, and refers to graphite having a fine structure. Graphitized polyimide refers to a polyimide produced by carbonizing polyimide and heat treatment.

In the second region 120, a hole is formed and at least a portion of the hole is filled with an adhesive, so that the adhesive strength between the heat dissipating layer and the electromagnetic wave shielding layer may be increased.

Holes formed in the second area 120 have a cross-sectional shape of at least one selected from circular, oval, square, rectangular, equilateral triangle, rhombus, regular pentagon, regular hexagon, star + type, x type, ㅏ type, type, and I type. Can be When the cross-sectional shape of the hole is circular, the average diameter can be 0.5 to 7 mm, the oval has a diameter ratio of inscribed and circumscribed circles of 1: 2 to 1: 10, and the + type has a diameter ratio of inscribed and circumscribed circles of 1: 2 to 1: May be 10.

The hole formed in the second region 120 may satisfy Equation 1 below. Through this, heat diffusion is excellent, peeling strength per hole is high, and vertical thermal conductivity may not increase:

[Equation 1]

0.070 ≤ release degree ≤ 1.750, preferably 0.300 ≤ release degree ≤ 1.500

(In Equation 1 above, the degree of release is (inner area of hole shape/circumference length of hole shape) ^1/2 )

The ratio of the total area of the portion in which the hole is formed among the total area of the second region 120 may be 1% to 30%, for example, 7% to 17%, and 7% to 15%. In the above range, the peel strength between the heat dissipation layer and the electromagnetic wave shielding layer may be excellent, and the heat diffusion performance may not be reduced.

Regarding the hole, it will be described with reference to FIG. 2.

2 is a top plan view of the second region 120 of the heat dissipation layer in the composite sheet according to the exemplary embodiment of the present invention.

Referring to FIG. 2A, the hole 111 may be formed to penetrate at least a portion of the thickness direction of the heat dissipation layer 100. In one embodiment, the thickness of the hole 111 may be 20% to 100%, for example, 50% to 100% of the thickness of the heat dissipation layer 100. In the above range, it is possible to increase the peel strength between the heat dissipation layer and the electromagnetic wave shielding layer. In the present specification, when the hole completely penetrates the heat dissipation layer, it is referred to as a "through hole".

The diameters of the holes 111 may be the same or different. For example, the diameters of the holes may be the same as shown in FIGS. 2A and 2B, or may be different from each other as shown in FIG. 2C. 2C shows that the diameter of the hole 111 gradually increases and then decreases from the interface between the first region 110 and the second region 120 ″ toward the distal end of the second region 120 ″. Is shown.

The holes 111 may be arranged in a line as shown in (A) and (C) of FIG. 2. However, as the holes 111 are formed to be alternately arranged in the second region 120 ′ as shown in FIG. 2B, it is possible to improve folding performance by canceling stress and/or tension during folding. The "alternating arrangement" refers to a case where the center of the next row of holes exists between the center of the hole and the center of the adjacent hole, assuming that a plurality of rows in which a plurality of holes are formed are arranged.

The ratio (D1/(D1 + D2)) of the average diameter (D1) of the holes 111 to the sum of the average diameter (D1) of the holes 111 and the minimum separation distance (D2) between the holes 111 is 4% To 64%, for example 6% to 47%. In the above range, heat dissipation can be improved and adhesion strength between electromagnetic wave shielding layers can be increased. When the cross-sectional shape is circular, the "average diameter" means a normal diameter, and when the cross-sectional shape is a circular shape, it is defined as the average of the sum of the length of the major axis and the length of the minor axis.

At least a portion of the hole 111 may be filled with an adhesive. Through this, the heat dissipation layer may have a high bonding strength to the electromagnetic wave shielding layer disposed thereon. 2A, 2B, and 2C illustrate a case where the hole is completely filled with a material forming the adhesive layer 300, but the present invention is not limited thereto.

In one embodiment, the adhesive filling the hole 111 may have an elongation of 600% or more, for example, 600% to 800%. In the above range, it may help to improve folding properties and folding durability. In the present specification, "elongation" may be measured by the method described in the experimental examples detailed below.

In another embodiment, the adhesive filling the hole 111 may have a cohesive force of 3.0kgf/inch or less, for example, 2.0kgf/inch to 2.5kgf/inch. In the above range, it may help to improve folding properties and folding durability. In the present specification, "cohesive force" can be measured by the method described in the experimental examples detailed below.

When the holes are filled with an adhesive that satisfies both the elongation and cohesiveness described above, the folding property of the present invention can be further improved.

At least a portion of the hole formed in the second region 120 may also be filled with an adhesive. The adhesive may include a conventional adhesive known to those skilled in the art, or may be filled with an adhesive that forms the adhesive layer 300 described below, thereby enhancing processability.

The thickness of the heat dissipation layer 110 may be 12 μm to 80 μm, specifically 14 μm to 50 μm. In the above range, there may be a heat dissipation effect.

Electromagnetic shielding layer

The electromagnetic shielding layer 200 is disposed on the upper surface of the heat dissipating layer 100 to implement an electromagnetic shielding function and a folding function. To this end, the electromagnetic wave shielding layer 200 has a structure in which the polyimide resin film layer 210 and the electromagnetic wave shielding functional layer 220 are segmented from each other.

The separation distance S21 between the polyimide resin film layer 210 and the electromagnetic wave shielding function layer 220 is 0.5% to 41%, for example, 2.3% to 8.2% of the total width of the first region 110 described above. Can be. When the composite sheet is folded through this, the stress is relieved by the hole in the first region and the separation distance between the first region and the second region in the heat dissipation layer, and the stress is relieved by the separation distance in the electromagnetic wave shielding layer, so that the entire composite sheet is You can make the folding durability good.

In one embodiment, the separation distance (S21) may be 0.1mm to 5mm, for example, 0.5mm to 1mm. In the above range, the polyimide resin film layer and the electromagnetic wave shielding function layer are not separated from each other during folding, and folding properties and durability may be provided.

1 shows a case where each end of the polyimide-based resin film layer 210 and the electromagnetic wave shielding function layer 220 is vertical. However, at least one of the ends of each of the polyimide resin film layer 210 and the electromagnetic wave shielding functional layer 220 may have a tapered shape.

The spaced space between the polyimide resin film layer 210 and the electromagnetic wave shielding function layer 220 may be filled with an adhesive.

In one embodiment, the adhesive may have an elongation of 600% or more, for example 600% to 800%. In the above range, durability is excellent during folding, and the polyimide-based resin film layer and the electromagnetic wave shielding function layer may not be separated from each other during folding. There is no particular limitation on the type of the adhesive that can implement the above-described elongation of 600% or more.

In one embodiment, the adhesive may have a cohesive force of 3.0kgf/inch or less, for example, 2.0kgf/inch to 2.5kgf/inch. In the above range, it may help to improve folding properties and folding durability. There is no particular limitation on the type of the adhesive capable of implementing the above-described cohesive force of 3.0 kgf/inch or less.

The polyimide resin film layer 210 may be disposed so that at least a portion of the heat dissipation layer 100 overlaps with the first region 110.

In one embodiment, 55% to 180% based on the total width of the polyimide-based resin film layer 210 and the width of each spaced space disposed on the left and right sides of the polyimide-based resin film layer 210 The portion of the heat dissipation layer 100 corresponding to is defined as the first region 110. In the above range, folding property and folding durability can be improved.

That is, the width of the first region 110 is 55 of the sum of the total width of the polyimide resin film layer 210 and the widths of each of the spaced spaces disposed on the left and right sides of the polyimide resin film layer 210 % To 180%.

The polyimide resin film layer 210 has excellent durability (e.g., heat resistance) at low and/or high temperatures, and was selected in consideration of the fact that the composite sheet may be repeatedly exposed at high temperatures when applied to a display device. .

The polyimide-based resin film layer 210 may be formed by employing a common type known to a person skilled in the art as a polyimide-based resin. For example, the polyimide-based resin may be prepared by solution polymerization of an aromatic dianhydrad and an aromatic diamine or an aromatic diisocyanate to prepare a polyamic acid derivative, followed by ring closure dehydration at a high temperature for imidization, but is not limited thereto.

The electromagnetic wave shielding functional layer 220 is a layer having heat dissipation and electromagnetic wave shielding functions, and may be a metal sheet or a cured layer of a resin composition.

In one embodiment, the metal sheet may be a copper foil, an aluminum foil, a copper alloy foil or an aluminum alloy foil, but is not limited thereto. Preferably, the metal sheet may be a copper foil or a copper alloy foil.

In another embodiment, the cured product layer of the resin composition may be a cured product of a mixed resin including a thermosetting epoxy resin, a rubber binder, a silane coupling agent, a fluorine-based surfactant, a soft magnetic powder, a moisture resistance agent, a curing agent and a curing accelerator. . The thermosetting epoxy resin, rubber binder, silane coupling agent, fluorine-based surfactant, curing agent, and curing accelerator are as described above in the adhesive layer below. Here, only the parts that differ from the adhesive layer will be described.

The rubber binder may be included in an amount of 160 to 350 parts by weight, preferably 180 to 300 parts by weight, more preferably 200 to 280 parts by weight, based on 100 parts by weight of the thermosetting epoxy resin. In the above range, the adhesive strength with the heat dissipating layer may be improved.

The silane coupling agent may be included in an amount of 4 to 25 parts by weight, preferably 4 to 18 parts by weight, more preferably 4 to 12 parts by weight, based on 100 parts by weight of the thermosetting epoxy resin. In the above range, there may be a dispersion effect of the particles, and there may be no agglomeration of the coping agents.

The fluorine-based surfactant may be included in an amount of 0.5 to 5 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the thermosetting epoxy resin. In the above range, there may be no problems in that the coating property is improved and the adhesion to the heat dissipating layer is poor.

Soft magnetic powder is one or two of Fe-Si-Al alloy, Fe-Si-Cr alloy, Fe-Si-B alloy, high flux, permalloy alloy, Ni-Zn ferrite, Mn-Zn ferrite The above can be mixed and used. The soft magnetic powder may be included in an amount of 700 to 1500 parts by weight, preferably 850 to 1350 parts by weight, more preferably 900 to 1300 parts by weight, based on 100 parts by weight of the thermosetting epoxy resin. The soft magnetic powder may have an average particle diameter of 20 to 100 μm, preferably 30 to 70 μm. In the above range, the electromagnetic wave shielding or electromagnetic wave absorption function is not deteriorated, and the coating property may be good.

The curing agent may be included in an amount of 5 to 20 parts by weight, preferably 8 to 17 parts by weight, based on 100 parts by weight of the thermosetting epoxy resin. In the above range, durability and adhesion to the heat dissipation layer may be improved.

The curing accelerator may be included in an amount of 1 to 5 parts by weight, preferably 1.5 to 4.5 parts by weight, based on 100 parts by weight of the thermosetting epoxy resin. In the above range, the curing speed may be increased to improve workability.

The electromagnetic shielding layer 200 may have a thickness of 5 μm to 72 μm, specifically 7.5 μm to 36 μm. In the above range, there may be an electromagnetic wave shielding effect.

Adhesive layer

The adhesive layer 300 is formed between the heat dissipation layer 100 and the electromagnetic wave shielding layer 200 to adhere the heat dissipation layer 100 and the electromagnetic wave shielding layer 200 to each other to maintain the shape of the composite sheet.

The adhesive layer 300 may have an elongation of 600% or more, for example, 600% to 800%. In the above range, when the composite sheet is folded, the heat dissipation layer and the electromagnetic wave shielding layer are not separated, so that folding properties and folding durability may be improved.

The adhesive layer 300 may have a cohesive force of 3.0kgf/inch or less, for example, 2.0kgf/inch to 2.5kgf/inch. In the above range, when the composite sheet is folded, the heat dissipation layer and the electromagnetic wave shielding layer are not separated, so that folding properties and folding durability may be improved.

The adhesive layer 300 may satisfy any one of the above-described elongation and cohesive force, but preferably, by satisfying both the elongation and cohesion, folding and folding durability can be further improved.

The adhesive layer 300 may be formed of an adhesive composition including a thermosetting epoxy resin, a rubber binder, a silane coupling agent, a fluorine-based surfactant, a curing agent, and a curing accelerator. If necessary, it may further include one or more selected from a flame retardant, a moisture resistant, and a thermally conductive filler.

The thermosetting resin may include at least one of a thermosetting epoxy resin, a thermosetting phenoxy resin, a thermosetting amino resin, a thermosetting polyester resin, and a thermosetting polyurethane resin, preferably a thermosetting epoxy resin, and more preferably A bisphenol A epoxy resin, a bisphenol F epoxy resin, a noblock epoxy resin, a halogen-containing epoxy resin, and the like may contain one or two or more.

When using a mixture of two or more thermosetting epoxy resins, it is recommended to mix and use bisphenol A epoxy resin and noblock epoxy resin in a weight ratio of 1: 0.15 to 1: 0.4, preferably 1: 0.18 to 1: 0.35. It is advantageous in terms of improving melting point and improving adhesion.

The rubber binder may play a role of imparting bending resistance, and includes at least one of acrylic rubber, silicone rubber, carboxylated nitrile elastomer, and phenoxy, and preferably one of acrylic rubber and silicone rubber. It may contain alone or two or more species. A carboxyl-based elastomer may be used, preferably a carboxyl nitrile elastomer. In addition, the carboxyl-based elastomer has a weight average molecular weight of 180,000 to 350,000, preferably a weight average molecular weight of 210,000 to 280,000, more preferably a weight average molecular weight of 215,000 to 255,000 to secure the bending resistance of the composite sheet. And it is advantageous in terms of securing heat resistance of the adhesive layer. In addition, the amount of the rubber binder may be 25 to 100 parts by weight, preferably 35 to 80 parts by weight, based on 100 parts by weight of the thermosetting resin. In the above range, when the composite sheet is bent due to poor flexibility of the cured adhesive layer, there is no problem that the joint portion between the electromagnetic shielding layer and the heat dissipation layer is partially peeled off, and the amount of other composition in the adhesive layer is relatively reduced, thereby reducing the adhesiveness of the adhesive layer. I can't.

The silane coupling agent plays a role of dispersing particles, and a general silane coupling agent used in the art can be used, preferably glycidoxy (C2 ~ C5 alkyl) trialkoxysilane. ), vinyltrialkoxysilane (Vinyltri(C2 ~ C5 alkoxy)silane and aminoethylaminopropylsilane triol), and more preferably glycidoxyethyltrimethoxysilane, One selected from glycidoxypropyltrimethoxysilane, glycidoxypropylethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, aminoethylaminopropylsilane triol can be used alone or in combination of two or more. In addition, the amount of the silane coupling agent to be used may be 1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the thermosetting resin. As a result, particle agglomeration may not occur.

As the fluorine-based surfactant serves to improve coating properties by lowering the surface tension, a general one used in the art may be used, and preferably, a fluorine-based aliphatic polymeric ester is used. As a specific example, FC443 of 3M, 4300 of Novec, and DuPont Capstone of DuPont may be used. The amount of the fluorine-based surfactant may be 0.01 to 2 parts by weight, preferably 0.02 to 1.2 parts by weight, based on 100 parts by weight of the thermosetting resin. In the above range, an effect of improving coating properties may be seen, and there may be no problem of lowering adhesion.

As the curing agent, at least one of an amine type curing agent, an acid anhydride type curing agent, and a phenol type curing agent may be used, and preferably, at least one of an amine type curing agent and an acid anhydride type curing agent may be included. For a specific example, 4,4'-diaminodiphenylsulfone may be used as a curing agent. The amount of the curing agent may be 1 to 20 parts by weight, preferably 1 to 17 parts by weight, based on 100 parts by weight of the thermosetting resin. In the above range, durability may not decrease and adhesion may not decrease.

The curing accelerator may include at least one of aromatic amines, aliphatic amines and aromatic tertiary amines, and preferably at least one of aromatic amines and aromatic tertiary amines. The amount of the curing accelerator may be 1 to 5 parts by weight, preferably 1.5 to 4.5 parts by weight, based on 100 parts by weight of the thermosetting resin. In the above range, the curing speed is high, so that workability is not deteriorated, and the problem that the cured layer is completely cured before hot pressing may not occur because the adhesive layer is rapidly cured.

The flame retardant is to obtain the flame retardant effect of the product, and a general one used in the art may be used, and preferably, one selected from among phosphorus-based flame retardants, inorganic flame retardants, and chlorinated flame retardants, or two or more kinds thereof can be mixed and used. , For a specific example, Clarit EXOLIT OP 935, ShowaDenko's H42M, Showa Denko's H32, Showa Denko's H43M, and the like can be used. The amount of the flame retardant to be used may be 30 to 60 parts by weight, preferably 35 to 55 parts by weight, based on 100 parts by weight of the thermosetting resin. In the above range, a flame retardant effect may be obtained, and a decrease in adhesion may not occur.

The moisture resistant agent is for controlling the moisture content in the adhesive layer and controlling the viscosity of the heat dissipating adhesive, and general ones used in the art can be used, and preferred examples include aluminum sulfate, latex, silicone emulsion, poly(organosiloxane), hydrophobic polymer It can be used alone or in combination of two or more selected from emulsions and silicone-based moisture resistant agents. The amount of the moisture resistant agent may be 0.5 to 10 parts by weight, preferably 1.5 to 8 parts by weight, based on 100 parts by weight of the thermosetting resin. In the above range, the effect by the injection of the moisture resistant agent may be obtained, and it may be easy to control an appropriate amount of moisture in the adhesive layer.

The adhesive layer may further apply a thermally conductive filler and/or a dispersant to provide a heat-dissipating adhesive function. As the thermally conductive filler, one type of graphite powder, carbon nanotube, carbon black, carbon fiber, ceramic and metal powder can be used alone or in combination of two or more, and preferably one type of graphite powder, ceramic and metal powder It can be used alone or in combination of two or more. When a thermally conductive filler is further used, it may be included in an amount of 45 to 1,100 parts by weight, preferably 75 to 800 parts by weight, based on 100 parts by weight of the thermosetting resin. In the above range, adhesion to the heat dissipation layer may decrease, and the vertical thermal conductivity of the composite sheet may not increase.

It may be preferable to use a thermally conductive filler having an average particle diameter of 3 μm to 25 μm. In the above range, there is no difficulty in dispersing particles, and there may be no reduction in thin film coating and adhesion.

As the dispersant, a general dispersant used in the art may be used, and preferably an acrylic block amine-based dispersant may be used.

The adhesive layer can control the viscosity and solid content of the adhesive by adding a mixture of the aforementioned curable resin, rubber binder, silane coupling agent, fluorine-based surfactant, curing agent, curing accelerator, flame retardant, and moisture-resistant agent to an organic solvent. The surface condition of the composition for forming the heat dissipating adhesive layer is improved through the process of controlling the bridge powder, and adhesion of the substrate and the orientation of the particles can be controlled. At this time, the organic solvent may be used alone or in combination of two or more of methyl ethyl ketone, toluene, tetrahydrofuran, and cyclohexanone.

After applying (or coating) the adhesive prepared with this composition and composition ratio on the top of the electromagnetic wave shielding layer, drying is performed to semi-cure to form an adhesive layer. It is preferable to apply the adhesive layer so that it has an average thickness of 2 μm to 25 μm, preferably an average thickness of 3 μm to 15 μm, and more preferably an average thickness of 4 μm to 8 μm based on the sheet. In the above range, the bonding force (or adhesion) between the electromagnetic wave shielding layer and the heat dissipating layer is not lowered, and it is economical and a thinning effect can be obtained.

Although not shown in FIG. 1, one or two or more of a thermoplastic polyurethane (TPU), a polyimide resin film layer, and a polyethylene naphthalate film layer may be additionally laminated and included on the lower surface of the heat dissipation layer.

Hereinafter, a method of manufacturing a composite sheet according to an embodiment of the present invention will be described.

In the composite sheet, a laminate in which a heat dissipation layer, an adhesive layer, and an electromagnetic wave shielding layer are stacked through a roll to roll mold punching and laminating process is put into a press or hot press (step 1); Heating and pressing the laminate to perform a press or hot press process (step 2); And separating the integrated composite sheet from the press or hot press (step 3).

The heat dissipation layer, the adhesive layer, and the electromagnetic wave shielding layer are as described above.

The press or hot press process may be performed under a pressure of 60° C. to 160° C. and 45 to 60 kgf/cm ^2. In the above range, the adhesive is melted in the adhesive layer, so that the adhesive strength is excellent, and the shape of the composite sheet can be well maintained.

The pressing or hot pressing process may be performed for 40 minutes to 80 minutes, preferably 50 minutes to 70 minutes at the temperature and pressure range. In the above range, the adhesive may be filled into the hole to increase the peel strength.

In the press or hot press process, heating may be performed by heating a hot press of 10° C. to 35° C. to 60° C. to 160° C. at a rate of 3° C./min to 5° C./min.

In step 3, cooling may be performed by cooling a hot press of 140°C to 160°C at a rate of 3°C/min to 5°C/min to 10°C to 35°C.

The composite sheet may be a to a 300 gf / cm ² to 700gf / cm ² when measuring the peel strength of the graphite layers 180 ° peel test (180 ° Peel Test) in accordance with JIS C 6741 specifications, preferably from 350 gf / cm ² to 650gf / cm ^2, may be more preferably 400 gf / cm ² to 620gf / cm ^2.

According to the JIS C 6741 standard, the composite sheet is 50 to 1,200 gf/hole, preferably 100 to 900 gf/hole, more preferably when the peel strength per hole is measured by 90° Peel Test. May be 200 to 750 gf/hole.

The composite sheet can be used as an electromagnetic wave shielding and heat dissipation component of electronic devices, and preferably, a digitizer, a smart phone, a tablet PC (tablet personal computer), a pebble, and a portable multimedia (PMP) that require a thinner thickness. player) or wearable electronic devices such as VR (Virtual Reality), smart watch, etc.

Hereinafter, a composite sheet according to another embodiment of the present invention will be described with reference to FIG. 3.

3 is a cross-sectional view in the thickness direction of a composite sheet according to another embodiment of the present invention.

Referring to FIG. 3, the composite sheet is substantially the same as the composite sheet of FIG. 1 except that reinforcing materials 400 formed to be spaced apart from each other are additionally stacked on the upper surface of the electromagnetic wave shielding layer 200. The reinforcing material may provide a structural reinforcement and support effect by being additionally formed on the composite sheet.

The stiffener 400 is composed of a first stiffener and a second stiffener formed to be spaced apart from each other. The reinforcing material may be formed to be spaced apart from each other to facilitate folding of the composite sheet.

The separation distance (S3) between the first and second stiffeners is the total width of the polyimide resin film layer 210 and the width of each of the separation spaces disposed on the left and right sides of the polyimide resin film layer 210 ( It may be 3% to 82% of the total sum of S21), for example 5% to 77%. In the above range, folding property and folding durability may be excellent.

The separation distance S3 between the first and second stiffeners may be 2% to 82%, for example, 5% to 77% of the maximum width of the first region 110 of the heat dissipation layer 100. In the above range, folding property and folding durability may be excellent.

The reinforcing material 400 may be one or more of stainless steel (SUS or STS, etc.), aluminum alloy, and polyimide resin film layer, but is not limited thereto.

The reinforcing material 400 may be adhered to the electromagnetic wave shielding layer 200 by an adhesive.

In one embodiment, the adhesive may have an elongation of 600% or more, for example 600% to 800%. In the above range, durability is excellent during folding, and the polyimide-based resin film layer and the electromagnetic wave shielding function layer may not be separated from each other during folding. There is no particular limitation on the type of the adhesive that can implement the above-described elongation of 600% or more.

In one embodiment, the adhesive may have a cohesive force of 3.0kgf/inch or less, for example, 2.0kgf/inch to 2.5kgf/inch. In the above range, it may help to improve folding properties and folding durability. There is no particular limitation on the type of the adhesive capable of implementing the above-described cohesive force of 3.0 kgf/inch or less.

Although not shown in FIG. 3, a plurality of reinforcements may be segmented and further disposed between the first and second reinforcements.

Hereinafter, a composite sheet according to another embodiment of the present invention will be described with reference to FIG. 4.

4 is a cross-sectional view in the thickness direction of a composite sheet according to another embodiment of the present invention.

Referring to FIG. 4, a laminate 500 of a thermoplastic polyurethane 510 and a polyimide resin film layer 520 may be additionally stacked and included on the lower surface of the heat dissipating layer 100.

The thermoplastic pulley urethane or polyimide resin film layer may be laminated on the lower surface of the heat dissipation layer to provide protection for the heat dissipation layer or reinforcing elongation.

The thermoplastic polyurethane or polyimide resin film layer may be adhered to the heat dissipation layer 100 by an adhesive.

In one embodiment, the adhesive may have an elongation of 600% or more, for example 600% to 800%. In the above range, durability is excellent during folding, and the polyimide-based resin film layer and the electromagnetic wave shielding function layer may not be separated from each other during folding. There is no particular limitation on the type of the adhesive that can implement the above-described elongation of 600% or more.

In one embodiment, the adhesive may have a cohesive force of 3.0kgf/inch or less, for example, 2.0kgf/inch to 2.5kgf/inch. In the above range, it may help to improve folding properties and folding durability. There is no particular limitation on the type of the adhesive capable of implementing the above-described cohesive force of 3.0 kgf/inch or less.

Hereinafter, a composite sheet according to another embodiment of the present invention will be described with reference to FIG. 5.

5 is a cross-sectional view in the thickness direction of a composite sheet according to another embodiment of the present invention.

Referring to FIG. 5, an adhesive layer 300 may be additionally stacked and included on the lower surface of the heat dissipation layer 100.

The adhesive layer 300 may allow the composite sheet to be adhered to another adherend.

In one embodiment, the adhesive may have an elongation of 600% or more, for example 600% to 800%. In the above range, durability is excellent during folding, and the polyimide-based resin film layer and the electromagnetic wave shielding function layer may not be separated from each other during folding. There is no particular limitation on the type of the adhesive that can implement the above-described elongation of 600% or more.

In one embodiment, the adhesive may have a cohesive force of 3.0kgf/inch or less, for example, 2.0kgf/inch to 2.5kgf/inch. In the above range, it may help to improve folding properties and folding durability. There is no particular limitation on the type of the adhesive capable of implementing the above-described cohesive force of 3.0 kgf/inch or less.

Hereinafter, a display device of the present invention will be described.

The display device of the present invention includes the composite sheet of the present invention. The display device of the present invention may be a flexible display device. However, as the composite sheet of the present invention can be used for non-flexible applications, the display device of the present invention may include a non-flexible display device. In one embodiment, the display device may include a light emitting display device including an organic light emitting diode, but is not limited thereto.

Hereinafter, the present invention will be described in more detail through examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Preparation Example 1: Preparation of adhesive

A carboxyl nitrile elastomer (weight average) based on 100 parts by weight of a thermosetting epoxy resin containing bisphenol A epoxy resin (K Chemical Co., brand name YD series resin) and Noblock epoxy resin (Kukdo Chemical, YDCN series resin) 1.25: 0.25 weight ratio Molecular weight 235,500~236,500) 55 parts by weight, silane coupling agent (Dow Corning, brand name Z6106) 1.5 parts by weight, fluorine-based surfactant (3M, brand name FC series surfactant) 0.1 parts by weight, 4,4'-diaminodi as a curing agent A mixture of 1.5 parts by weight of phenyl sulfone, 2.5 parts by weight of a curing accelerator (manufactured by Shikoku), 2.8 parts by weight of a moisture resistant agent (Japan S company, KP series), and 41 parts by weight of a flame retardant (Swiss C company OP series) is mixed with methyl as an organic solvent. Into ethyl ketone and stirred to prepare an adhesive.

For the adhesive layer formed of the prepared adhesive, the elongation was 700% when evaluated by the Tensile Test (ASTM D 638) method. Cohesive strength for the adhesive layer formed of the prepared adhesive was 2.5kgf/inch when evaluated by ASTM D 903 method.

Preparation Example 2: Preparation of heat dissipation layer

A second region was formed with a graphite sheet (DASSEN, DSN5017X), a plurality of polyimide resin films were stacked on the first region, and holes were formed in the second region. At this time, specific specifications of the holes formed in the second region are shown in Table 1 below.

Preparation Examples 3 to 18 : Preparation of heat dissipation layer

In Preparation Example 2, a heat dissipation layer was manufactured in the same manner as in Preparation Example 2, except that the specifications of the first region and the second region were changed as shown in Table 1 below.

Area 1 Area 2 Each thickness of the polyimide resin film
(㎛) Total number of polyimide resin films Separation distance of polyimide resin film (㎛) ratio(%) Hole cross-section shape Lee Hyung-do Manufacturing Example 2 7.5 3 5 69.23% circle 1.500 Manufacturing Example 3 7.5 3 5 69.23% Oval 1.297 Manufacturing Example 4 7.5 3 5 69.23% + Type 0.393 Manufacturing Example 5 7.5 3 5 69.23% square 1.500 Manufacturing Example 6 7.5 3 5 69.23% Rectangle 0.750 Manufacturing Example 7 7.5 3 5 69.23% Equilateral triangle 0.866 Manufacturing Example 8 7.5 3 5 69.23% Rhombus 1.500 Manufacturing Example 9 7.5 3 5 69.23% Regular pentagon 0.688 Manufacturing Example 10 7.5 3 5 69.23% Regular hexagon 0.866 Manufacturing Example 11 7.5 3 5 69.23% Star model 0.449 Manufacturing Example 12 7.5 3 5 69.23% x type 0.393 Manufacturing Example 13 7.5 3 5 69.23% Type H 0.405 Manufacturing Example 14 7.5 3 5 69.23% B brother 0.429 Manufacturing Example 15 7.5 3 5 69.23% I type 0.393 Manufacturing Example 16 7.5 3 3 78.95% circle 1.500 Manufacturing Example 17 7.5 3 10 52.94% circle 1.500 Manufacturing Example 18 7.5 5 10 48.39% circle 1.500

*Ratio: The ratio of the total thickness of the polyimide resin film to the total thickness of the first region

Example 1

The electromagnetic wave shielding layer was prepared using a polyimide resin film (SKC Kolon PI, GF050) and copper foil.

After applying the adhesive of Preparation Example 1 on the heat dissipation layer prepared in Preparation Example 2 was semi-cured. On the semi-cured adhesive, a polyimide resin film and a copper foil were arranged in the shape of FIG. 1 and put into a hot press process. A composite sheet was prepared by pressing at 140° C. and 45 kgf/cm ^{2 in a hot press.} Specific specifications of the prepared composite sheet are shown in Table 2 below.

Examples 2 to 21

In Example 1, a composite sheet was manufactured in the same manner as in Example 1, except that each specification of the composite sheet was changed as shown in Table 2 below.

Example 22

The electromagnetic wave shielding layer was prepared using a polyimide resin film (SKC Kolon PI, GF050) and copper foil. SUS was used as a reinforcing material.

After applying the adhesive of Preparation Example 1 on the heat dissipation layer prepared in Preparation Example 2 was semi-cured. On the semi-cured adhesive, a polyimide resin film and copper foil were placed in the shape of FIG. 1, and SUS was placed thereon, and then put into a hot press process. A composite sheet was prepared by pressing at 140° C. and 45 kgf/cm ^{2 in a hot press.} Specific specifications of the prepared composite sheet are shown in Table 2 below.

Examples 23 to 25

In Example 22, a composite sheet was prepared in the same manner as in Example 1, except that each specification of the composite sheet was changed as shown in Table 2 below.

Comparative Example 1

In Example 1, a composite sheet was prepared in the same manner as in Example 1, except that a heat radiation layer was formed only with a graphite layer without lamination of a polyimide resin film among the heat radiation layers.

Comparative Example 2

In Example 1, a composite sheet was prepared in the same manner as in Example 1, except that the electromagnetic wave shielding layer was composed of only copper foil without a polyimide resin film.

Comparative Example 3

In Example 1, a composite sheet was prepared in the same manner as in Example 1, except that the polyimide resin film and the copper foil were not separated from each other.

glue Heat dissipation layer Separation distance (mm) Width ratio (%) Ratio when reinforcing material is included (%) Example 1 Manufacturing Example 1 Manufacturing Example 2 0.5 92.9% - Example 2 Manufacturing Example 1 Manufacturing Example 2 One 100.0% - Example 3 Manufacturing Example 1 Manufacturing Example 2 2 114.3% - Example 4 Manufacturing Example 1 Manufacturing Example 2 5 157.1% - Example 6 Manufacturing Example 1 Manufacturing Example 3 0.5 92.9% - Example 7 Manufacturing Example 1 Manufacturing Example 4 0.5 92.9% - Example 8 Manufacturing Example 1 Manufacturing Example 5 0.5 92.9% - Example 9 Manufacturing Example 1 Manufacturing Example 6 0.5 92.9% - Example 10 Manufacturing Example 1 Manufacturing Example 7 0.5 92.9% - Example 11 Manufacturing Example 1 Manufacturing Example 8 0.5 92.9% - Example 12 Manufacturing Example 1 Manufacturing Example 9 0.5 92.9% - Example 13 Manufacturing Example 1 Manufacturing Example 10 0.5 92.9% - Example 14 Manufacturing Example 1 Manufacturing Example 11 0.5 92.9% - Example 15 Manufacturing Example 1 Manufacturing Example 12 0.5 92.9% - Example 16 Manufacturing Example 1 Manufacturing Example 13 0.5 92.9% - Example 17 Manufacturing Example 1 Manufacturing Example 14 0.5 92.9% - Example 18 Manufacturing Example 1 Manufacturing Example 15 0.5 92.9% - Example 19 Manufacturing Example 1 Manufacturing Example 16 0.5 92.9% - Example 20 Manufacturing Example 1 Manufacturing Example 17 0.5 92.9% - Example 21 Manufacturing Example 1 Manufacturing Example 18 0.5 92.9% - Example 22 Manufacturing Example 1 Manufacturing Example 2 0.5 92.9% 5.38% Example 23 Manufacturing Example 1 Manufacturing Example 2 0.5 92.9% 7.1% Example 24 Manufacturing Example 1 Manufacturing Example 2 0.5 92.9% 31.3% Example 25 Manufacturing Example 1 Manufacturing Example 2 0.5 92.9% 45.5% Comparative Example 1 Manufacturing Example 1 - 0.5 92.9% - Comparative Example 2 Manufacturing Example 1 Manufacturing Example 2 - - - Comparative Example 3 Manufacturing Example 1 Manufacturing Example 2 0 0 -

* Separation distance: The separation distance between the polyimide resin film and copper foil among the electromagnetic wave shielding layers

*Width ratio: the ratio of the width of the first area to the total width of the polyimide resin film and the widths of each spaced space disposed on the left and right sides of the polyimide resin film (S22 + 2 x S21)

*Ratio when reinforcing materials are included: The separation distance between reinforcing materials for the total width of the polyimide resin film and the widths of the respective separation spaces arranged on the left and right sides of the polyimide resin film (S22 + 2 x S21) ) Of the ratio

The following physical properties were evaluated for the prepared composite sheet, and the results are shown in Tables 3, 6, and 7 below.

(1) Folding test: The prepared composite sheet was cut into a rectangle having a length of 10.15 cm of copper foil and a width of 15 cm of copper foil to prepare a specimen. The folding test was evaluated at 25°C using a folder switch (Weget Automation System, Folding Fatigue tester). The specimen was folded in the longitudinal direction of the specimen, but the folding speed was 43,000 times per day (30RPM), the bending angle was 1.5mm, and the folding angle was 0° and 181°.

After folding evaluation, for each of the left (A) of the folding part (the first area), the middle part of the folding part (B), the right of the folding part (C), and the interface between the polyimide resin film and the copper foil (D). The evaluation result was evaluated visually. It evaluated according to the following evaluation criteria.

(Circle): There is no lifting or generation of air bubbles.

△: There is some lifting and generation of air bubbles.

Ⅹ: It cannot be used because it is uplifted and air bubbles are severely generated.

(2) Thermal diffusivity: The composite sheet was cut into 15 cm in the length direction of the copper foil and 2.5 cm in the width direction of the copper foil, and a double-sided tape was attached to the copper foil side. The prepared sample is attached to a heating block, and the temperature of the heating block is raised to 90°C. Next, the heating block was sealed in the box and then stabilized for 10 minutes, and the temperature was measured using an IR camera. The highest temperature (hot spot, Th) and lowest temperature (cold spot, Tc) portion of the composite sheet was measured, and the temperature difference (ΔT) of the composite sheet was measured to measure the thermal diffusivity of the composite sheet. The lower the ΔT, the better the thermal diffusivity, indicating excellent heat dissipation performance. Thermal conductivity was evaluated according to the following criteria.

○: When Th -Tc temperature difference △T is less than 50% of Th temperature

△: When the temperature difference between Th -Tc △T is 50% or more and less than 55% of the Th temperature

Ⅹ: When Th -Tc temperature difference △T is 55% or more of Th temperature

Folding test Thermal diffusivity A B C D Th Tc △T level
direction segment
part Example 1 ○ ○ ○ ○ 76.3 43.1 33.2 ○ ○ Example 2 ○ ○ ○ ○ 78 41.6 36.4 ○ ○ Example 3 ○ ○ ○ △ 74.4 41.9 32.5 ○ ○ Example 4 △ ○ △ ○ 70.7 37.5 33.2 ○ ○ Example 6 △ ○ △ ○ 67.4 41.8 25.6 ○ ○ Example 7 ○ ○ ○ ○ 82 41.8 40.2 ○ ○ Example 8 △ ○ △ ○ 71.2 42 29.2 ○ ○ Example 9 ○ ○ ○ ○ 81.2 43.5 37.7 ○ ○ Example 10 ○ ○ ○ ○ 83.1 42.8 40.3 ○ ○ Example 11 ○ ○ ○ ○ 75.9 44.8 31.1 ○ ○ Example 12 ○ ○ ○ ○ 73.5 48.3 25.2 ○ ○ Example 13 ○ ○ ○ ○ 78.5 41.9 36.6 ○ ○ Example 14 ○ ○ ○ ○ 82.8 42.4 40.4 ○ ○ Example 15 ○ ○ ○ ○ 76.2 41 35.2 ○ ○ Example 16 △ ○ △ ○ 67.5 40.2 27.3 ○ ○ Example 17 △ ○ △ ○ 66.5 42.6 23.9 ○ ○ Example 18 △ ○ △ ○ 65.3 40.8 24.5 ○ ○ Example 19 △ ○ △ ○ 64.4 37.8 26.6 ○ ○ Example 20 ○ ○ ○ △ 64.8 37.5 27.3 ○ ○ Example 21 △ ○ △ ○ 54.8 28.4 26.4 ○ △ Example 22 ○ ○ ○ △ 54.8 27.6 27.2 ○ ○ Example 23 △ ○ △ ○ 54.2 27.7 26.5 ○ △ Example 24 ○ ○ ○ ○ 54.2 28.5 25.7 ○ ○ Example 25 ○ ○ ○ ○ 54.1 28.2 25.9 ○ ○ Comparative Example 1 ○ ○ △ △ 56.7 28.7 28 ○ △ Comparative Example 2 △ ○ △ △ 56.9 27.9 29 △ △ Comparative Example 3 X ○ X ○ 81.6 38 43.6 △ ○

As shown in Tables 3, 6, and 7, the composite sheet of the present invention has excellent horizontal thermal conductivity, excellent heat dissipation effect, and excellent folding property and folding durability.

On the other hand, Comparative Example 1 without a polyimide resin film layer among the heat dissipation layers had a problem in that the folding characteristics were deteriorated, and Comparative Example 2 in which the electromagnetic wave shielding layer was made only of copper foil without a polyimide resin film had a weak copper foil layer or There was a problem that the shielding effect and folding characteristics were deteriorated due to destruction, and Comparative Example 3 in which the polyimide-based resin film and the copper foil were not separated from each other had poor folding properties and the heat dissipation effect was also poor compared to the Example.

Simple modifications or changes of the present invention can be easily implemented by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (19)

A heat radiation layer, an electromagnetic wave shielding layer laminated on an upper surface of the heat radiation layer, and an adhesive layer laminated between the heat radiation layer and the electromagnetic wave shielding layer,
The heat dissipation layer is composed of a first region and a second region disposed on both sides of the first region, and the first region has a laminate structure of a plurality of laminated polyimide films,
The electromagnetic wave shielding layer comprises a polyimide-based resin film layer and an electromagnetic wave shielding functional layer spaced apart from each other on both sides of the polyimide-based resin film layer.
The composite sheet according to claim 1, wherein a ratio of the total thickness of the polyimide-based resin film in the first region to the total thickness of the first region is 25% to 95%.
The composite sheet according to claim 1, wherein a separation distance between the polyimide-based resin films in the first region is 3 μm to 20 μm.
The composite sheet according to claim 1, wherein the first region is filled with an adhesive.
The composite sheet according to claim 4, wherein the adhesive has an elongation of 600% or more and a cohesive force of 3.0kgf/inch or less.
The composite sheet according to claim 1, wherein a plurality of holes are formed in the second region.
The composite sheet according to claim 1, wherein at least a part of the hole is filled with an adhesive.
The composite sheet for electromagnetic wave shielding and heat dissipation according to claim 1, wherein a separation distance between the polyimide resin film layer and the electromagnetic wave shielding function layer is 0.5% to 41% of the total width of the first region.
The composite sheet according to claim 1, wherein a separation distance between the polyimide resin film layer and the electromagnetic wave shielding function layer is 0.1mm to 5mm.
The composite sheet according to claim 1, wherein each end of the polyimide resin film layer and the electromagnetic wave shielding functional layer is vertical or tapered.
The method of claim 1, wherein the width of the first region is 55% to a total of the total width of the polyimide resin film layer and the widths of each spaced space disposed on the left and right sides of the polyimide resin film layer. That is 180%, a composite sheet for electromagnetic shielding and heat dissipation.
The composite sheet according to claim 1, wherein the electromagnetic wave shielding functional layer is a metal sheet or a cured layer of a resin composition.
The composite sheet according to claim 12, wherein the metal sheet is a copper foil, an aluminum foil, a copper alloy foil or an aluminum alloy foil.
The composite sheet according to claim 1, wherein the adhesive layer has an elongation of 600% or more and a cohesive force of 3.0kgf/inch or less.
The electromagnetic wave of claim 1, wherein one or two or more of a thermoplastic polyurethane (TPU), a polyimide resin film layer, and a polyethylene naphthalate film layer are additionally laminated on the lower surface of the heat dissipation layer. Composite sheet for shielding and heat dissipation.
The composite sheet for electromagnetic wave shielding and heat dissipation according to claim 1, wherein reinforcing materials formed spaced apart from each other are additionally stacked on the upper surface of the electromagnetic wave shielding layer.
The method of claim 1, wherein the separation distance between the reinforcing materials is a total of the total width (S22) of the polyimide resin film layer and the width (S21) of each separation space disposed on the left and right sides of the polyimide resin film layer. That will be 3% to 82% of the composite sheet for electromagnetic shielding and heat dissipation.
The composite sheet according to claim 17, wherein the reinforcing material comprises at least one of stainless steel, thermoplastic polyurethane (TPU), and polyimide resin film layer.
A display device comprising a composite sheet for shielding and dissipating electromagnetic waves according to any one of claims 1 to 18.

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