KR102176129B1 - Heat radiation sheet and EMI shielding-Heat radiation composite sheet comprising the same - Google Patents

Abstract

The present invention relates to a heat dissipation sheet and an electromagnetic wave shielding-radiation composite sheet comprising the same, and more particularly, excellent horizontal thermal conductivity and electromagnetic wave shielding property, as well as remarkably excellent interlayer adhesion, and applied to a display as no surface curvature occurs. The present invention relates to a heat dissipation sheet exhibiting very excellent visibility and an electromagnetic wave shielding-radiation composite sheet including the same.

Description

Heat radiation sheet and EMI shielding-Heat radiation composite sheet comprising the same}

The present invention relates to a heat dissipation sheet and an electromagnetic wave shielding-radiation composite sheet comprising the same, and more particularly, excellent horizontal thermal conductivity and electromagnetic wave shielding property, as well as remarkably excellent interlayer adhesion, and applied to a display as no surface curvature occurs. The present invention relates to a heat dissipation sheet exhibiting very excellent visibility and an electromagnetic wave shielding-radiation composite sheet including the same.

In recent years, as electric and electronic devices become more high-performance, light and thin, the demand for heat dissipation sheets that can effectively dissipate heat generated from heat sources such as semiconductor parts and light emitting parts embedded therein is steadily increasing. Functionalization is required.

In general, the heat dissipation sheet uses copper foil, copper foil/graphite laminate, graphite sheet part, etc., but copper foil has both heat dissipation and electromagnetic wave shielding properties, but when the thickness increases, it lacks flexibility, and heat conduction in the horizontal direction is graphite. It does not reach the level and has a limit in weight reduction due to its high density. In addition, if the thickness exceeds about 52 μm, flexibility is insufficient, and thus it is limited to be applied as a heat dissipating sheet having a complex shape.

Meanwhile, an electromagnetic wave is a phenomenon in which energy moves in a sinusoidal shape while an electric field and a magnetic field are interlocked, and is usefully used in electronic devices such as wireless communication and radar. The electric field is generated by a voltage and is easily shielded by an obstacle such as a tree or a distance being increased, while the magnetic field is generated by an electric current and is inversely proportional to the distance, but is not easily shielded.

Recent electronic devices are sensitive to electromagnetic interference (EMI) generated by an internal interference source or an external interference source, and there is a concern that a malfunction of the electronic device may be caused by electromagnetic waves. In addition, users who use electronic devices may also be adversely affected by electromagnetic waves generated from the electronic devices.

Accordingly, in recent years, interest in electromagnetic wave shielding materials for protecting parts of electronic devices or human bodies from electromagnetic wave generating sources or electromagnetic waves radiated from the outside is increasing rapidly.

Meanwhile, commercial products composed of various materials are widely used as electromagnetic wave shielding sheets to block electromagnetic waves, but conventional electromagnetic wave shielding sheets have low thermal conductivity and thus cannot obtain sufficient heat dissipation effect. Therefore, various heat dissipation and electromagnetic wave shielding functions are applied. Composite sheets are being developed.

However, even with this development, the conventional composite sheet can exhibit heat dissipation characteristics and electromagnetic wave shielding properties, but there is a problem in that the interlayer adhesion is not very good, and to solve this problem, a through hole is formed in the heat dissipating member provided in the composite sheet. Although the interlayer adhesion was improved, there was a problem in that the visibility was significantly lowered when applied to a display due to the occurrence of curvature on the surface of the composite sheet.

Accordingly, it is urgent to develop a composite sheet that exhibits excellent horizontal thermal conductivity and electromagnetic wave shielding properties, remarkably excellent interlayer adhesion, and no surface curvature, and thus exhibits very excellent effects in visibility when applied to a display.

Republic of Korea Patent Publication No. 2015-0077238 (published date: 2015-07-07)

The present invention was conceived to solve the above-described problems, and at the same time excellent horizontal thermal conductivity and electromagnetic wave shielding property, remarkably excellent interlayer adhesion, and excellent visibility when applied to a display as no surface curvature occurs. It is an object of the present invention to provide a heat radiation sheet and an electromagnetic wave shielding-radiation composite sheet including the same.

In order to solve the above-described problems, the present invention is provided on one or both sides of a graphite sheet part, and in a heat dissipation sheet including an adhesive layer having a total thickness smaller than the average thickness of the graphite sheet part, a graphite sheet part provided with a plurality of through holes ; And an adhesive layer formed on one or both surfaces of the graphite sheet portion, and an adhesive portion including a reinforcing member, which is an adhesive agent extended from the adhesive layer and filled in the through hole.

According to an embodiment of the present invention, the adhesive layer and the reinforcing member are each independently selected from the group consisting of acrylic resin, urethane resin, epoxy resin, silicone rubber, acrylic rubber, carboxyl nitrile elastomer, phenoxy and polyimide resin. It may be formed of a composition for forming an adhesive portion including a main resin having more than one species.

In addition, the adhesive part forming composition comprises at least one selected from the group consisting of an epoxy-based curing agent, an isocyanate-based curing agent, a secondary amine-based curing agent, a tertiary amine-based curing agent, a melamine-based curing agent, an isocyanate-based curing agent, and a phenolic curing agent. It may further include a curing agent.

In addition, the adhesive layer may be formed of a first adhesive portion forming composition further comprising 0.05 to 10 parts by weight of the curing agent based on 100 parts by weight of the main resin, and the reinforcing member contains the curing agent based on 100 parts by weight of the main resin. It may be formed of a second adhesive portion forming composition further comprising 2.5 to 30 parts by weight.

In addition, the adhesive layer may be formed of a composition for forming a first adhesive portion containing a first resin, the reinforcing member may be formed of a composition for forming a second adhesive portion containing a second resin, and the second resin The weight average molecular weight of may be greater than the weight average molecular weight of the first resin.

In addition, the first subject resin may have a weight average molecular weight of 200,000 to 800,000, and the second subject resin may have a weight average molecular weight of 300,000 to 1,000,000.

In addition, the tensile strength of the reinforcing member may be 150 to 500% of the tensile strength of the adhesive layer.

In addition, the adhesive layer may have a tensile strength of 0.5 to 20 N/mm2, and the reinforcing member has a tensile strength of 1.5 It may be ~ 30 N/mm2.

In addition, the adhesive portion may include a first adhesive layer and a second adhesive layer respectively provided on the upper and lower surfaces of the graphite sheet portion, and the first adhesive layer and the second adhesive layer may each independently have an average thickness of 2 to 10 μm. have.

In addition, the graphite sheet portion may have an average thickness of 17 to 105 μm.

On the other hand, the present invention supports; Electromagnetic wave shielding unit; And interposed between the support part and the electromagnetic wave shielding part, the above-described heat dissipation sheet; It provides an electromagnetic wave shielding-radiation composite sheet comprising a.

According to an embodiment of the present invention, the support part may include at least one selected from the group consisting of polyimide, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), and the electromagnetic wave shielding part may be made of copper foil or aluminum foil. I can.

In addition, the support portion may have an average thickness of 10 to 77 μm, and the electromagnetic wave shielding portion may have an average thickness of 4 to 52 μm.

The heat dissipation sheet according to the present invention and the electromagnetic wave shielding-radiation composite sheet including the same are excellent in horizontal thermal conductivity and electromagnetic wave shielding properties, and at the same time, have remarkably excellent interlayer adhesion, and have very excellent visibility when applied to a display as no surface curvature occurs. Can represent.

1 is a cross-sectional view of a heat dissipation sheet according to an embodiment of the present invention,
Figure 2 is a cross-sectional view of the electromagnetic shielding-radiation composite sheet according to an embodiment of the present invention, and,
3 is a schematic view showing a through hole formed in a graphite sheet portion provided in a heat dissipation sheet according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein. In the drawings, parts not related to the description are omitted in order to clearly describe the present invention, and the same reference numerals are added to the same or similar components throughout the specification.

In the heat dissipation sheet provided on one or both sides of the graphite sheet part and including an adhesive layer having a total thickness smaller than the average thickness of the graphite sheet part, as shown in FIG. 1, the heat dissipation sheet 1000 according to an embodiment of the present invention A graphite sheet portion 100 provided with a plurality of through holes; And an adhesive layer 210 formed on one or both surfaces of the graphite sheet portion 100 and a reinforcing member 220 that is an adhesive extended from the adhesive layer 210 and filled into the through hole. It is implemented with.

First, the graphite sheet portion 100 will be described.

The graphite sheet part is implemented as a graphite sheet part in which through holes are formed, and interlayer adhesion can be remarkably improved through such through holes.

The graphite sheet part may be used without limitation as long as it is a general graphite sheet part commonly used in the art, and a graphite sheet part including at least one of pyrolytic graphite and graphitized polyimide may be used. .

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 may have a very well-developed microstructure.

The graphitized polyimide may be prepared through the following graphitization process. First, as a preparatory step of the graphitization process, the polyimide may be added to the sintering furnace by laminating on a natural graphite sheet. Such a preparatory step may be performed in order to prevent the polyimide from fusion between the films. Next, as a first step of the graphitization process, a carbonization treatment step of polyimide may be performed at a temperature of 600° C. to 1,800° C. for 2 to 7 hours. Through this carbonization process, nitrogen, hydrogen, and components other than carbon in the polyimide can be removed. Finally, as a second step of the graphitization process, a heat treatment step may be performed at a temperature of 2,000°C to 3,200°C. Different alignments of the carbon atoms can be caused through such heat treatment steps. Specifically, after step 1, pores may exist between the stacks of carbon in the polyimide, and heat dissipation performance by increasing the density and removing pores by passing through a rolling roll at a temperature of 2,000°C to 3,200°C. This maximized graphitized polyimide can be produced.

On the other hand, the through hole may be a through hole 1 formed at regular intervals as shown in FIG. 3, may be a through hole 2 formed at different intervals and alternately arranged, and randomly formed through holes ( 3), but is not limited thereto.

In addition, although the shape of the through-hole is shown in a circular shape in FIG. 3, this is only to aid understanding of the present invention, and there is no limitation on the cross-sectional shape of the through-hole provided in the graphite sheet of the present invention. As an example, the cross-sectional shape of the through hole may be circular, polygonal, cross-shaped, C-shaped, four-leafed, six-leafed, eight-leafed, etc., and these shapes may be used alone, or the cross-sectional shapes may be used for purpose and use. As it may be mixed and used, the present invention does not specifically limit it.

In addition, the area of the through-holes of the graphite sheet part 100 is 2% to 30%, preferably 3.5% to 15%, more preferably 3.5% to 10% of the total area of the upper or lower surface of the graphite layer. In this case, if the through-hole area is less than 2%, interlayer adhesion may be reduced, and if it exceeds 30%, there may be a problem that the water quality thermal conductivity is lowered.

Meanwhile, the graphite sheet portion 100 may have an average thickness of 17 to 105 μm, preferably 17 to 100 μm, more preferably 17 to 60 μm, and even more preferably 25 to It may be 40 μm. When the average thickness of the graphite sheet portion 100 is less than 17 μm, the desired level of heat dissipation characteristics cannot be expressed, and when the average thickness exceeds 105 μm, interlayer adhesion may be relatively lowered.

Next, the bonding portion 200 will be described.

As described above, the adhesive portion 200 includes an adhesive layer 210 formed on one or both surfaces of the graphite sheet portion 100 and a reinforcing member 220 that is an adhesive extending from the adhesive layer 210 and filled into the through hole. ).

The adhesion part 200 performs a function of remarkably improving the interlayer adhesion of the heat dissipation sheet 1000, and the reinforcing member 220 included in the adhesion part 200 improves the adhesion between layers of the heat dissipation sheet 1000 and at the same time bends on the surface. It performs the function of reinforcing so that this does not occur.

The adhesive layer 210 and the reinforcing member 220 are each independently at least one selected from the group consisting of acrylic resin, urethane resin, epoxy resin, silicone rubber, acrylic rubber, carboxyl nitrile elastomer, phenoxy and polyimide resin, Preferably, it may be formed of a composition for forming an adhesive portion including a main resin having an acrylic resin.

In addition, the adhesive portion forming composition is at least one selected from the group consisting of an epoxy-based curing agent, an isocyanate-based curing agent, a secondary amine-based curing agent, a tertiary amine-based curing agent, a melamine-based curing agent, an isocyanate-based curing agent, and a phenolic curing agent, preferably For example, it may further include a curing agent having an epoxy-based curing agent.

In this case, the adhesive layer 210 may be formed of a composition for forming a first adhesive portion further comprising 0.05 to 10 parts by weight of the curing agent, preferably 0.1 to 2.0 parts by weight, based on 100 parts by weight of the main resin. If the curing agent provided in the first adhesive part forming composition is less than 0.05 parts by weight based on 100 parts by weight of the main resin, the adhesive layer may be uncured, so that the desired level of interlayer adhesion cannot be expressed, and 10 parts by weight If it is exceeded, the desired level of interlayer adhesion cannot be expressed due to a decrease in adhesion due to overcuring.

In addition, the composition for forming the first adhesive portion forming the adhesive layer 210 may include a first resin having a weight average molecular weight of 200,000 to 800,000, and preferably a weight average molecular weight of 200,000 to 600,000. If the weight average molecular weight of the first main resin included in the first adhesive part forming composition does not satisfy the above range, the desired level of interlayer adhesion may not be achieved due to a decrease in adhesion.

Meanwhile, the total thickness of the adhesive layer 210 formed on one or both surfaces of the graphite sheet portion 100 may be smaller than the average thickness of the graphite sheet portion 100. Accordingly, it may be advantageous in terms of thinning, and when the heat dissipation sheet 1000 is formed with a limited thickness, the heat dissipation property may be excellent as the thickness of the graphite sheet portion 100 may be relatively thick.

In addition, as described above, the adhesive layer 210 may include a first adhesive layer 211 and a second adhesive layer 212 respectively provided on the upper and lower surfaces of the graphite sheet part 100. Accordingly, as the adhesion to the reinforcing member 220, which is an adhesive to be described later, may be more excellent, it may be more advantageous in terms of improving interlayer adhesion.

In this case, the first adhesive layer 211 and the second adhesive layer 212 may each independently have an average thickness of 2 to 10 μm, and preferably 3 to 8 μm. If the average thickness of the first adhesive layer 211 and the second adhesive layer 212 is less than 2 μm, interlayer adhesion may be lowered. If the average thickness exceeds 10 μm, it is not preferable in terms of thinning, and heat dissipation to a limited thickness. When the sheet 1000 is formed, the heat dissipation characteristics may be deteriorated as the thickness of the graphite sheet portion 100 becomes relatively thin, which is not very desirable.

On the other hand, the first main resin and the curing agent provided in the first adhesive portion forming composition may be the same as the second main resin and the curing agent provided in the second adhesive portion forming composition to be described later, and in this case, the above-described adhesive layer and a reinforcing member to be described later As the compatibility between the layers is excellent, it may be more advantageous in terms of improving interlayer adhesion.

In addition, the reinforcing member 220 is a reinforcing member 220, which is an adhesive extended from the adhesive layer 210 and filled into the through hole, as described above, wherein the reinforcing member 220 is 100 weight of the main resin It may be formed of a composition for forming a second adhesive portion further comprising 2.5 to 30 parts by weight of the curing agent, preferably 3.0 to 12.0 parts by weight with respect to the part. If the curing agent provided in the second adhesive part forming composition is less than 2.5 parts by weight based on 100 parts by weight of the main resin, the function of reinforcing the surface to not be curved is insignificant, resulting in surface curvature, and when applied to a display. Visibility may be deteriorated, and if it exceeds 30 parts by weight, the desired level of interlayer adhesion cannot be expressed due to a decrease in adhesion due to overcuring.

In addition, the composition for forming the second adhesive portion forming the reinforcing member 220 may include a second resin having a weight average molecular weight of 300,000 to 1,000,000, preferably 300,000 to 800,000. If the weight average molecular weight of the second main resin provided in the second adhesive part forming composition is less than 300,000, the function of reinforcing the formed reinforcing member to prevent the surface from being curved is insignificant, resulting in surface curvature, and when applied to a display Visibility may decrease. In addition, when the weight average molecular weight exceeds 1,000,000, the adhesive strength decreases due to excessive stiffness, so that the desired level of interlayer adhesion cannot be expressed.

Meanwhile, the weight average molecular weight of the second main resin may be greater than the weight average molecular weight of the first main resin.

Meanwhile, the reinforcing member 220 may have an average thickness of 10 to 110 μm, preferably an average thickness of 17 to 105 μm, more preferably 17 to 100 μm, and even more preferably 17 to It may be 60 μm, more preferably 25 to 40 μm, and most preferably the same as the graphite layer thickness. If the thickness of the reinforcing member 220 is outside the above range, surface curvature may occur, and visibility may decrease when applied to a display.

Meanwhile, the tensile strength of the reinforcing member 220 may be 150 to 500%, preferably 200 to 400%, compared to the tensile strength of the adhesive layer 210. If the tensile strength of the reinforcing member 220 is less than 150% of the tensile strength of the adhesive layer 210, the function of reinforcing the surface to not be curved is insignificant, resulting in surface curvature, and visibility when applied to a display It may be lowered, and if it exceeds 500%, the adhesive strength is lowered and the desired level of interlayer adhesion cannot be expressed.

In addition, at this time, the adhesive layer 210 has a tensile strength of 0.5 ~ 20N/mm ² It may be, and preferably the tensile strength is 1 ~ 15N/mm ² May be, the reinforcing member 220 has a tensile strength of 1.5 ~ 30N/mm ² May be, preferably the tensile strength is 2 ~ 25N / mm ² Can be If the tensile strength of the reinforcing member is less than the above range, the function of reinforcing the surface to not be curved is insignificant, resulting in surface curvature, and when applied to a display, visibility may be deteriorated. It is lowered, and the desired level of interlayer adhesion cannot be expressed.

On the other hand, referring to Figure 2, electromagnetic wave shielding-radiation composite sheet 1001 according to an embodiment of the present invention includes a support 310; Electromagnetic wave shielding part 410; And the above-described heat dissipation sheet 1000 interposed between the support part 310 and the electromagnetic wave shielding part 410.

At this time, a graphite sheet portion 100' of the heat dissipation sheet 1000 provided in the electromagnetic wave shielding-radiation composite sheet 1001, an adhesive portion 200' including an adhesive layer 210' and a reinforcing member 220', The description of the first adhesive layer 211 ′ and the second adhesive layer 212 ′ includes the graphite sheet portion 100 ′, the adhesive layer 210 ′, and the reinforcing member 220 ′ provided in the heat dissipation sheet 1000 described above. As the descriptions of the included adhesive portion 200 ′, the first adhesive layer 211 ′, and the second adhesive layer 212 ′ are the same, the description will be omitted.

First, the support part 310 will be described.

The support part 310 performs a function of supporting the electromagnetic wave shielding-heating composite sheet 1001, and any material that can be used to perform the role of a support part generally in the art may be used without limitation. It may include one or more selected from the group consisting of mid, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN), and more preferably polyimide.

Meanwhile, the support part 310 may have an average thickness of 10 to 77 μm, preferably 12 to 75 μm, and more preferably an average thickness of 25 to 50 μm. If the average thickness of the support part 310 is less than 10 μm, the durability of the electromagnetic wave shielding-radiation composite sheet 1001 may be deteriorated, and if the average thickness exceeds 77 μm, interlayer adhesion may decrease.

Next, the electromagnetic wave shielding part 410 will be described.

The electromagnetic wave shielding part 410 is a material having heat dissipation and electromagnetic wave shielding functions, and may be used without limitation as long as it is a general metal foil that can be used in the art, preferably copper foil or aluminum foil.

Further, the electromagnetic wave shielding part 410 may have an average thickness of 4 to 52 μm, preferably 5 to 50 μm. If the average thickness of the electromagnetic wave shielding part 410 is less than 4 μm, the electromagnetic wave shielding power and heat dissipation characteristics may be deteriorated, and tearing may occur. If it exceeds 52 μm, thinning becomes difficult and flexibility may decrease. have.

Meanwhile, the electromagnetic wave shielding-radiating composite sheet 1001 according to the present invention may further include an adhesive member (not shown) formed on one surface of the support part 310.

The adhesive member performs a function of adhering to the display when the electromagnetic shielding-heating composite sheet is applied to the display, and according to the present invention, any material that can form an adhesive member can be used without limitation in the art. In the following, this is not particularly limited. As an example, the adhesive member may be a PSA adhesive member.

In addition, the electromagnetic wave shielding-heating composite sheet 1001 according to the present invention may further include a protective layer (not shown) formed on one surface of the electromagnetic wave shielding part 410.

The protective layer protects the electromagnetic wave shielding-radiation composite sheet 1001, and performs a function of protecting the display when the electromagnetic wave shielding-heating composite sheet 1001 is applied to the display, and is commonly used as a protective layer in the art. As long as the material can be used without limitation, the present invention does not specifically limit it.

Meanwhile, the electromagnetic wave shielding-heating composite sheet of the present invention may be manufactured through a manufacturing method described below, but is not limited thereto.

Electromagnetic wave shielding-radiation composite sheet according to the present invention comprises: forming a plurality of through holes in the graphite sheet; Filling a reinforcing member, which is an adhesive, into the through hole of the graphite sheet part; Forming an adhesive layer on one or both sides of a graphite sheet portion filled with a reinforcing member to prepare a heat dissipation sheet; And forming a support portion and an electromagnetic wave shielding portion on the upper and lower portions of the heat dissipating sheet, respectively.

On the other hand, according to another embodiment of the present invention, when the composition for forming the adhesive portion forming the reinforcing member and the adhesive layer is the same, the step of filling the reinforcing member as an adhesive into the through hole of the graphite sheet portion is not separately performed, and the adhesive layer When forming the graphite sheet portion by filling the through hole with an adhesive reinforcing member, the adhesive layer and the reinforcing member may be formed at the same time.

The heat dissipation sheet according to the present invention and the electromagnetic wave shielding-radiation composite sheet including the same are excellent in horizontal thermal conductivity and electromagnetic wave shielding properties, and at the same time, have remarkably excellent interlayer adhesion, and have very excellent visibility when applied to a display as no surface curvature occurs. Can represent.

The present invention will be described in more detail through the following examples, but the following examples do not limit the scope of the present invention, which should be interpreted to aid understanding of the present invention.

<Example 1>

(1) Manufacture of heat dissipation sheet

First, through a punching process, a plurality of through holes are formed in a graphite sheet portion having a thickness of 25 μm, and an acrylic rubber having a weight average molecular weight of 400,000 as a second main resin in the plurality of through holes and 100 parts by weight of the second main resin As a curing agent, a reinforcing member, which is an adhesive, is filled through a composition for forming a second adhesive containing 3.0 parts by weight of an epoxy-based curing agent, and an acrylic having a weight average molecular weight of 300,000 as a primary resin on both sides of the graphite sheet part filled with the reinforcing member. Heat dissipation as shown in FIG. 1 by forming a first adhesive layer and a second adhesive layer each having a thickness of 5 μm with a composition for forming a first adhesive part containing 0.1 parts by weight of an epoxy-based curing agent as a curing agent with respect to 100 parts by weight of rubber and the first resin. The sheet was prepared. At this time, the tensile strength of the reinforcing member measured by ASTM D638 method using UTM equipment is 2.0 N/mm ² And, the tensile strength of the adhesive layer is 1.0 N/mm ² Was.

(2) Manufacture of electromagnetic shielding-heat radiating composite sheet

After preparing a laminate by providing a polyimide film having a thickness of 25 μm as a support part and a copper foil having a thickness of 18 μm as an electromagnetic wave shielding part on the upper part of the prepared heat dissipation sheet, the An electromagnetic wave shielding-heat radiating composite sheet as shown in FIG. 2 was prepared by using the laminate as a roll laminator.

<Examples 2 to 11 and Comparative Example 1>

Prepared in the same manner as in Example 1, but the weight average molecular weight of the second main resin provided in the second adhesive part forming composition, the content of the curing agent, the weight average molecular weight of the first main resin provided in the first adhesive part forming composition, and curing agent By changing the content of and the presence or absence of a reinforcing member, an electromagnetic wave shielding-heat radiating composite sheet as shown in Tables 1 to 2 was prepared.

<Experimental Example>

The following physical properties were evaluated for the electromagnetic wave shielding-radiation composite sheet prepared in Examples and Comparative Examples and shown in Tables 1 to 2.

One. Per through hole Peel strength( gf /Hole) measurement

The electromagnetic wave shielding-radiation composite sheet prepared according to Examples and Comparative Examples was measured by preparing a specimen according to JIS C 6741 standard, and performing a peel strength per through hole by a 180° Peel Test.

2. Thermal diffusion ability Measure

The electromagnetic wave shielding-radiation composite sheet prepared according to Examples and Comparative Examples was cut into a size of 100 mm×10 mm horizontally × vertically, and a double-sided tape was attached to one side of the electromagnetic wave shielding part.

Next, the prepared sample is attached to a heating block and the temperature of the heating block is raised to 80°C (evaluation proceeds by raising the temperature to 80°C, which is the level of the heating temperature of the AP chip in the smart phone).

Next, after sealing the heating block in the box and stabilizing for 10 minutes, the temperature is measured using an IR camera to determine the hot spot and the cold spot of the composite sheet. Measurements were made, and the thermal diffusivity of the composite sheet was measured by determining their temperature difference. At this time, the smaller the difference ㅿT value between the two temperatures, the better the heat dissipation performance.

3. Electromagnetic shielding performance evaluation

Electromagnetic wave shielding-radiation composite sheets prepared according to Examples and Comparative Examples were evaluated for electromagnetic wave shielding performance in the 1 GHz band using a vector network analyzer (Anritsu Corporation).

4. Visibility evaluation

The electromagnetic wave shielding-radiation composite sheet prepared according to Examples and Comparative Examples was visually inspected using a roll inspection machine. Specifically, the manufactured electromagnetic shielding-heating composite sheet was hung on a roll inspection machine to perform a visual inspection on the appearance of the lower electromagnetic shielding layer, and the visibility test result was obtained by measuring the thickness using a micrometer after product manufacturing. The results were confirmed.

At this time, compared to the thickness of the graphite sheet, when a difference in thickness of ±4㎛ occurs-○, when a difference in thickness of ±8㎛ occurs-△, when a difference in thickness exceeds ±8㎛-×.

division Example
One Example
2 Example
3 Example
4 Example
5 Adhesive layer The first subject balance Weight average molecular weight 300,000 210,000 600,000 1,000,000 300,000 Hardener Content (parts by weight) 0.1 0.1 0.1 0.1 0.1 Tensile strength (N/㎟) One 0.7 5 12 One Reinforcing member 2nd subject balance Weight average molecular weight 400,000 250,000 800,000 1,200,000 400,000 Hardener Content (parts by weight) 3 3 3 3 1.5 Tensile strength (N/㎟) 2 1.8 14 23 1.6 Included or not ○ ○ ○ ○ ○ Tensile strength of the reinforcing member compared to the adhesive layer (%) 200 257 280 192 160 Peeling strength per through hole (gf/Hole) 430 438 421 379 439 Heat dissipation performance (ㅿT) 21.74 21.77 21.75 21.73 21.76 Electromagnetic shielding performance (dB) -69.6 -69.6 -69.6 -69.6 -69.6 Visibility evaluation ○ × ○ ○ ×

division Example
6 Example
7 Example
8 Example
9 Example
10 Comparative example
One Fold
Wear
layer Week 1
Resin Weight average molecular weight 600,000 600,000 400,000 150,000 1,000,000 300,000 Hardener Content (parts by weight) 2 0.1 3 0.03 15 0.1 Tensile strength (N/㎟) 7.7 5 2 0.4 23 One Bo
River
part
ashes Week 2
Resin Weight average molecular weight 400,000 400,000 400,000 250,000 1,200,000 - Hardener Content (parts by weight) 12 35 3 1.5 35 - Tensile strength (N/㎟) 16 26 2 1.3 34 - Included or not ○ ○ ○ ○ ○ - Tensile strength of the reinforcing member compared to the adhesive layer (%) 208 520 100 325 152 - Peeling strength per through hole (gf/Hole) 424 376 434 446 342 189 Heat dissipation performance (ㅿT) 21.76 21.72 21.75 -21.78 -21.71 23.47 Electromagnetic shielding performance -69.6 -69.6 -69.6 -69.6 -69.6 -69.6 Visibility evaluation ○ ○ △ × ○ ×

As can be seen from Tables 1 to 2,

The weight average molecular weight of the second main resin provided in the second adhesive part forming composition according to the present invention, the content of the curing agent, the weight average molecular weight of the first main resin provided in the first adhesive part forming composition, the content of the curing agent and the presence or absence of a reinforcing member, etc. Examples 1, 3 and 6 satisfying all of these, compared to Examples 2, 4, 5, 7 to 10 and Comparative Example 1 in which any one of them is omitted, have excellent interlayer peel strength, and heat dissipation performance and electromagnetic wave shielding power At the same time, it was possible to achieve both excellent effects with excellent visibility at the same time.

Although an embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in the present specification, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same idea. It will be possible to easily propose other embodiments by changing, deleting, adding, etc., but it will be said that this is also within the scope of the present invention.

1, 2, 3: through hole
100, 100': graphite sheet part
200, 200': adhesive part
210, 210': adhesive layer
211, 211': first adhesive layer
212, 212': second adhesive layer
220, 220': reinforcing member
301: support
401: electromagnetic wave shield
1000: heat dissipation sheet
1001: electromagnetic shielding-radiation composite sheet

Claims (13)

In the heat dissipation sheet comprising an adhesive layer provided on one or both sides of the graphite sheet portion, the total thickness is less than the average thickness of the graphite sheet portion,
Graphite sheet portion provided with a plurality of through holes; And
An adhesive portion including an adhesive layer formed on one or both surfaces of the graphite sheet portion, and a reinforcing member that is an adhesive extended from the adhesive layer and filled into the through hole; and
The adhesive layer is formed of a first adhesive portion forming composition comprising 0.05 to 10 parts by weight of a curing agent based on 100 parts by weight of the first main resin having a weight average molecular weight of 200,000 to 800,000,
The reinforcing member is formed of a composition for forming a second adhesive portion comprising 2.5 to 30 parts by weight of a curing agent based on 100 parts by weight of the second main resin having a weight average molecular weight of 300,000 to 1,000,000,
The tensile strength of the reinforcing member is 150 to 500% of the tensile strength of the adhesive layer.
Heat dissipation sheet. The method of claim 1,
The first and second base resins are each independently at least one heat dissipation sheet selected from the group consisting of acrylic resin, urethane resin, epoxy resin, silicone rubber, acrylic rubber, carboxyl nitrile elastomer, phenoxy and polyimide resin . The method of claim 1,
The curing agent is each independently at least one selected from the group consisting of an epoxy-based curing agent, an isocyanate-based curing agent, a secondary amine-based curing agent, a tertiary amine-based curing agent, a melamine-based curing agent, an isocyanic acid-based curing agent, and a phenolic curing agent. delete The method of claim 1,
The heat dissipation sheet having a weight average molecular weight of the second main resin is greater than the weight average molecular weight of the first main resin. delete delete The method of claim 1,
The adhesive layer has a tensile strength of 0.5 to 20 N/mm2,
The reinforcing member is a heat dissipation sheet having a tensile strength of 1.5 ~ 30 N/㎟. The method of claim 1,
The adhesive portion includes a first adhesive layer and a second adhesive layer respectively provided on the upper and lower surfaces of the graphite sheet portion,
Each of the first adhesive layer and the second adhesive layer independently has an average thickness of 2 to 10 μm. The method of claim 1,
The graphite sheet portion is a heat dissipation sheet having an average thickness of 17 ~ 105㎛. Support;
Electromagnetic wave shielding unit; And
Interposed between the support portion and the electromagnetic wave shielding portion, the heat dissipation sheet according to any one of claims 1 to 3, 5 and 8 to 10; electromagnetic wave shielding-radiation composite sheet comprising. The method of claim 11,
The support includes one or more selected from the group consisting of polyimide, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN),
The electromagnetic shielding part is a copper foil or an aluminum foil electromagnetic shielding-heat radiating composite sheet. The method of claim 11,
The support portion has an average thickness of 10 ~ 77㎛,
The electromagnetic wave shielding unit has an average thickness of 4 ~ 52㎛ electromagnetic shielding-radiation composite sheet.

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