KR20230046051A - Composite and method for manufacturing the composite - Google Patents

Abstract

Provided are a composite material and a manufacturing method of the composite material. The composite material of the present application has excellent heat dissipation properties as well as electrical insulation properties. Therefore, a heat generated in an electronic component, and so on can be effectively dissipated and overcurrent or electric leakage can be blocked. Additionally, the composite material has a simple process and can be manufactured in large areas. The composite material comprises a metal sheet and a nanowire layer.

Description

Composite and method for manufacturing the composite

This application relates to composites and methods of manufacturing composites.

As the treatment of heat generated from electric products, electronic products, or batteries such as secondary batteries has become an important issue, various heat dissipation measures have been proposed. Among thermally conductive materials used for heat dissipation measures, a resin composition in which a thermally conductive filler is blended with a resin is known.

There was a case where a metal or carbon material was applied as a thermally conductive filler to such a resin composition, but in this case, heat dissipation characteristics were improved, but electrical conductivity was also improved, so its use in electronic parts was limited.

On the other hand, in order to secure excellent heat dissipation characteristics and low electrical conductivity, a large amount of ceramic heat dissipation filler may be applied to the resin. Patent Document 1 (Korean Patent Publication No. 10-2016-0105354) discloses a battery module to which such a resin composition is applied. However, in this case, there was a disadvantage that the cured product of the resin composition became hard and the durability was weak.

In addition, among the heat conductive materials used for the heat dissipation countermeasure, a material in which a ceramic coating layer is introduced into a metal surface has been used in some cases. Here, there is a method of forming the ceramic coating layer by chemical vapor deposition of silane (SiH ₄ ) gas, but this method uses toxic gas and has disadvantages in large-area manufacturing. In addition, there is a method of forming a ceramic coating layer by plating silicon (Si) on a metal surface, but there is a disadvantage in that it is difficult to uniformly plate on a large area and to have a sufficient thickness. In addition, there is a method of forming a ceramic coating layer by patterning a photoresist into a nanoscale using electron beam lithography equipment and etching silicon into a nanoscale using the patterned photoresist as a mask, but this process is complicated and the manufacturing cost is high. The disadvantage is that it is not suitable for mass production.

Accordingly, a composite material that can be used as a thermally conductive material by securing excellent heat dissipation characteristics and electrical insulation properties at the same time and is easy to manufacture even in a large area has been required.

Republic of Korea Patent Publication No. 10-2016-0105354

The present application can provide a composite material capable of effectively dissipating heat generated in electronic components and blocking overcurrent or electric leakage by securing excellent heat dissipation characteristics and electrical insulation at the same time.

The present application can provide a manufacturing method of the composite material that is simple in process and can be manufactured in a large area.

Among the physical properties mentioned in this application, if the measurement temperature affects the physical property, the corresponding physical property is a physical property measured at room temperature unless otherwise specified. As used in this application, room temperature is a natural temperature that is not heated or cooled, for example, any temperature within the range of 10 ° C to 30 ° C, for example, about 15 ° C or higher, about 18 ° C or higher, It may mean a temperature of about 20 ° C or higher, about 23 ° C or higher, about 27 ° C or lower, or 25 ° C.

The terms a to b used in this application mean within the range between a and b while including a and b. For example, including a to b parts by weight is the same as meaning included within the range of a to b parts by weight.

The term nano size or nano used in this application may mean, but is not limited thereto, greater than or equal to 1 nm and less than 1,000 nm.

The term metal foam used in this application refers to a porous structure containing metal as a main component. Including metal as a main component in the above means that the ratio of the metal based on the total weight of the metal foam is 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, 80% by weight or more, It may mean a case of 85% by weight or more, 90% by weight or more, or 95% by weight or more. The upper limit of the ratio of the metal included as the main component is not particularly limited. For example, the proportion of the metal may be less than or equal to 100% by weight or less than 100% by weight.

The term porosity used in this application means that the porosity is at least 30% or more, 35% or more, 40% or more, 45% or more, 50% or more, 55% or more, 60% or more, 65% or more, 70% or more. It may mean a case of more than 75% or more or 80% or more. The upper limit of the porosity is not particularly limited, and may be, for example, less than about 100%, less than about 99%, or less than about 98%. The porosity can be calculated by a known method by calculating the density of the metal foam.

The term metal foil used in this application means a thin film containing metal as a main component. Including metal as a main component in the above means that the ratio of the metal based on the total weight of the metal foam is 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, 80% by weight or more, It may mean a case of 85% by weight or more, 90% by weight or more, or 95% by weight or more. The upper limit of the ratio of the metal included as the main component is not particularly limited. For example, the proportion of the metal may be less than or equal to 100% by weight or less than 100% by weight.

Part by weight, a term used in this application, refers to the ratio of the weight of each component unless otherwise specified.

The term excellent electrical insulation used in this application means that the sheet resistance measured by 4-point probe sheet resistance measurement is about 1 mΩ/□ or more, 2 mΩ/□ or more, 3 mΩ/□ or more, 4 mΩ/□ or more, 5 mΩ/□ or more. It can mean more than □ or more than 6 mΩ/□. Specifically, the thermal diffusivity may be measured according to the method for measuring physical properties below.

Excellent thermal diffusivity, as a term used in this application, is about 10 mm ² /s or more, 12 mm ² /s or more, 14 mm when measured in the horizontal direction (in-plane direction) through the ASTM D4935 standard. ² /s or more, 16 mm ² /s or more, 18 mm ² /s or more, 20 mm ² /s or more, or 22 mm ² /s or more. Specifically, the thermal diffusivity may be measured according to the method for measuring physical properties below.

composite

A composite material according to an example of the present application may include a metal sheet and a nano wire layer.

According to an example of the present application, the thickness of the nanowire layer may be 1 μm or more, 1.25 μm or more, 1.5 μm or more, 1.75 μm or more, 2 μm or more, 2.25 μm or more, 2.5 μm or more, 2.75 μm or more, or 3 μm or more. . In another example, the thickness of the nanowire layer may be 20 μm or less, 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, or 10 μm or less. The thickness of the nanowire layer may be within a range formed by appropriately selecting the upper and lower limits listed above. In addition, when the nanowire layer has a thickness within the above range, desired thermal diffusivity and electrical insulation properties can be secured.

According to an example of the present application, the ratio (A2/A1) between the thickness A1 of the metal sheet and the thickness A2 of the nanowire layer may be in the range of 0.001 to 10, 0.005 to 8, or 0.001 to 5. In addition, when the thickness ratio (A2/A1) satisfies the above range, excellent thermal diffusivity and electrical insulation properties can be secured even in a large area.

The material of the metal sheet according to an example of the present application is not particularly limited, but is selected from the group consisting of copper, gold, silver, aluminum, nickel, iron, cobalt, magnesium, molybdenum, tungsten, and zinc in order to secure thermal diffusivity. Any selected metal or an alloy of two or more of the above may be included.

In addition, the metal sheet according to an example of the present application may be a material having high thermal conductivity. The metal sheet has a thermal conductivity of about 8 W/mK or more, about 10 W/mK or more, about 15 W/mK or more, about 20 W/mK or more, about 25 W/mK or more, about 30 W/mK or more, about 35 W/mK or more, about 40 W/mK or more, about 45 W/mK or more, about 50 W/mK or more, about 55 W/mK or more, about 60 W/mK or more, about 65 W/mK or more, about 70 W/mK or greater, about 75 W/mK or greater, about 80 W/mK or greater, about 85 W/mK or greater, or about 90 W/mK or greater. The thermal conductivity is not particularly limited because, as the value is higher, desired thermal control characteristics can be secured while using a smaller amount of the metal sheet, and may be, for example, about 1,000 W/mK or less.

A metal sheet according to an example of the present application may be a metal foil or a metal foam.

In addition, the metal foil or metal foam may be in the form of a film. In this case, the thickness of the film may be adjusted in consideration of a desired thermal diffusivity or thickness ratio in manufacturing a composite material according to a method described below. The thickness of the film may be, for example, about 10 μm or more, about 20 μm or more, about 30 μm or more, about 40 μm or more, about 45 μm or more, or about 50 μm or more in order to secure the desired thermal conductivity. The upper limit of the thickness of the film is controlled according to the purpose and is not particularly limited, but is, for example, about 1,000 μm or less, about 900 μm or less, about 800 μm or less, about 700 μm or less, about 600 μm or less, or about 500 μm or less. It may be on the order of μm or less.

Thickness, a term used in this application, may be the minimum thickness, maximum thickness, or average thickness of the object when the thickness of the object is not constant.

Various metal foils and metal foams that can be used in an example of the present application are known, and various methods of manufacturing the metal foils and metal foams are also known. In the present application, such a known metal foil or metal form or a metal foil or metal form manufactured by the known method may be applied.

As a method for producing a metal foam, a method of sintering a composite material of a pore former such as salt and a metal, a method of coating a metal on a support such as a polymer foam and sintering in the state, a slurry method, and the like are known.

The metal foam that can be used in one example of the present application may be manufactured according to a method for manufacturing a metal foam including sintering a metal foam precursor containing a metal component.

A metal foam precursor according to an example of the present application refers to a structure before a process performed to form a metal foam, such as the sintering, that is, a structure before the metal foam is generated. In addition, even if the metal foam precursor is called a porous metal foam precursor, it does not necessarily have to be porous per se, and if it can form a metal foam, which is a porous metal structure, it can be called a porous metal foam precursor for convenience. .

The metal foam precursor according to an example of the present application may be formed of a slurry including a metal component, a dispersant, and a binder.

Metal powder may be applied as the metal component. Examples of the metal powder that can be applied are not particularly limited to those determined according to the purpose, and examples thereof include copper powder, gold powder, silver powder, aluminum powder, nickel powder, iron powder, cobalt powder, magnesium powder, and molybdenum powder. , any one powder selected from the group consisting of tungsten powder and zinc powder, a metal powder in which two or more of the above are mixed, or a powder of an alloy of two or more of the above.

As the dispersant, for example, alcohol may be applied. As alcohol, methanol, ethanol, propanol, pentanol, octanol, ethylene glycol, propylene glycol, pentanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, glycerol, texanol Alternatively, a monohydric alcohol having 1 to 20 carbon atoms such as terpineol or a dihydric alcohol having 1 to 20 carbon atoms or more polyhydric alcohols such as ethylene glycol, propylene glycol, hexanediol, octanediol or pentanediol may be used. However, the type is not limited to the above.

The type of the binder is not particularly limited, and may be appropriately selected depending on the type of metal component or dispersing agent used in preparing the slurry. For example, as the binder, an alkyl cellulose having an alkyl group having 1 to 8 carbon atoms such as methyl cellulose or ethyl cellulose, a polyalkylene carbonate having an alkylene unit having 1 to 8 carbon atoms such as polypropylene carbonate or polyethylene carbonate, or A polyvinyl alcohol-based binder such as polyvinyl alcohol or polyvinyl acetate (hereinafter, may be referred to as a polyvinyl alcohol compound) may be exemplified, but is not limited thereto.

In addition, the metal foam is a prior application of the present applicant, Korean Application Nos. Alternatively, it may be manufactured according to the method disclosed in No. 2016-0162152 or the like.

A nano wire layer according to an example of the present application may include one or more nano wires formed on at least one surface of a metal sheet. That is, the nanowire layer may refer to an aggregate of nanowires formed on at least one surface of the metal sheet.

A nanowire according to an example of the present application means a wire structure having a predetermined length and thickness, a nanoscale thickness, and a longer length than the thickness. 1 simply shows the structure of a composite material according to an example of the present application. As shown in FIG. 1 , the nanowire layer 20 may refer to an assembly of nanowires 21 formed on at least one surface of the metal sheet 10 . That is, the surface of the nanowire layer 20 according to an example of the present application may not be flat due to the nanowire 21 .

The nanowire constituting the nanowire layer according to an example of the present application has a thickness (D) of 10 nm or more, 12.5 nm, 15 nm or more, 17.5 nm or more, 20 nm or more, 22.5 nm or more, 25 nm or more, 27.5 nm or more, or 30 nm or more. In another example, the nanowire may have a thickness (D) of 300 nm or less, 275 nm or less, 250 nm or less, 225 nm or less, 200 nm or less, 175 nm or less, or 150 nm or less. The thickness of the nanowire may be within a range formed by appropriately selecting the above upper and lower limits.

The nanowire constituting the nanowire layer according to an example of the present application has a length (L) of 1 μm or more, 1.5 μm or more, 2 μm or more, 2.5 μm or more, 3 μm or more, 3.5 μm or more, 4 μm or more μm or more, 4.5 μm or more, 5 μm or more, 5.5 μm or more, 6 μm or more, 6.5 μm or more, 7 μm or more, 7.5 μm or more, 8 μm or more, 8.5 μm or more, or 9 μm or more. In another example, the nanowire has a length (L) of 100 μm or less, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, or 10 μm or less It may be less than μm. The length of the nanowire may be within a range formed by appropriately selecting the above upper and lower limits. In addition, the length of the nanowire may determine the thickness of the nanowire layer of the composite material. In an example of the present application, the length of the nanowire (average length when there are a plurality of nanowires) may be the thickness of the nanowire layer of the composite material.

When the thickness and length of the nanowires satisfy the above ranges, the composite material may have excellent electrical conductivity.

The thickness (D) and length (L) of the nanowire can be measured using a scanning electron microscope (SEM), and when the nanowire is one, it means its thickness and length, and when the nanowire is plural. In this case, it may be their average thickness and average length.

The nanowire constituting the nanowire layer according to an example of the present application may include an insulating material to secure electrical insulation of the composite material. Insulation means electrical insulation unless otherwise specified in this application.

The insulating material can be used without particular limitation as long as it is a known material having electrical insulating properties, but may be silicon (Si), which is easy to form nanowires. In addition, considering the ease of formation of the nanowire, it may be advantageous that the insulating material does not substantially include an oxide. As used in this application, the term "substantially not included" may mean that the component is not intentionally included, and if the component is not intentionally included, it may be said that the component is not substantially included even if it is naturally included. . In addition, the substantially not included may mean less than 1% by weight, less than 0.1% by weight, less than 0.01% by weight, or less than 0.001% by weight relative to the total weight even if it is naturally included.

The composite material according to an example of the present application has a sheet resistance of about 1 mΩ/□ or more, 2 mΩ/□ or more, 3 mΩ/□ or more, 4 mΩ/□ or more, 5 mΩ/□ or more, measured by 4-point probe sheet resistance measurement. or 6 mΩ/□ or greater. The higher the sheet resistance, the better the electrical insulation. The upper limit is not particularly limited, but the sheet resistance of the composite material may be about 100 mΩ/□ or less within a range having thermal diffusion performance. The sheet resistance of the composite material may be within a range formed by appropriately selecting the above upper and lower limits.

The composite material according to an example of the present application has a thermal diffusivity of about 35 mm ² /s or more, 37 mm ² /s or more, 39 mm ² /s or more, measured in the horizontal direction (in-plane direction) through the ASTM D4935 standard, 41 mm ² /s or more, 43 mm ² /s or more, 45 mm ² /s or more, or 47 mm ² /s or more. The higher the thermal diffusivity, the better the heat dissipation characteristics. The upper limit is not particularly limited, but the thermal diffusivity of the composite material may be about 120 mm ² /s or less. The thermal diffusivity of the composite material may be within a range formed by appropriately selecting the upper limit and the lower limit described above.

Manufacturing method of composite material

A method of manufacturing a composite material according to an example of the present application includes coating an insulating material dispersion on at least one surface of a metal sheet and heat-treating the metal sheet coated with the insulating material dispersion, wherein the coating step includes dip coating. (dip coating), it may be to perform at least one selected from the group consisting of blade coating and spin coating. When the metal sheet is a metal foam, dip coating may be suitable for uniform coating in consideration of internal pores.

The manufacturing method of the composite material according to an example of the present application can be manufactured by a simple method, unlike the conventional complicated and high manufacturing cost process, and is easy to manufacture even in a large area. Here, the large area means a case where the width and length are more than several tens of cm (for example, about 210 Х 297 mm). In the prior art, it was difficult to form a nanowire layer when it was several tens of cm or more for reasons such as using gas. However, the method for manufacturing a composite material according to an example of the present application includes dip coating, blade coating, and spin coating. By performing at least one selected from the group consisting of, it is possible to manufacture a nanowire layer even in a large area.

In the method for manufacturing a composite material according to an example of the present application, the insulating material dispersion may include an insulating material and a dispersion solvent. Despite the name of the dispersion, the insulating material dispersion may refer to a state in which the insulating material is contained in a dispersion solvent, and preferably may refer to a state in which the insulating material is dispersed in a dispersion solvent.

In the method for manufacturing a composite material according to an example of the present application, the insulating material may be any known material having electrical insulation properties without particular limitation, but may be silicon (Si) powder, which is easy to form nanowires. In addition, considering the ease of formation of the nanowire, it may be advantageous that the insulating material does not substantially include an oxide.

In the method for manufacturing a composite material according to an example of the present application, the insulating material has an average particle diameter of 100 nm or more, 120 nm or more, 140 nm or more, 160 nm or more, 180 nm or more, 200 nm or more, 220 nm or more, 240 nm or more. nm or more, 260 nm or more, 280 nm or more, or 300 nm or more. In another example, the insulating material has an average particle diameter of 2,000 nm or less, 1,900 nm or less, 1,800 nm or less, 1,700 nm or less, 1,600 nm or less, 1,500 nm or less, 1,400 nm or less, 1,300 nm or less, 1,200 nm or less, 1,100 nm or less or less than 1,000 nm. The average particle diameter of the insulating material may be within a range formed by appropriately selecting the above upper and lower limits. In addition, when the average particle diameter of the insulating material satisfies the above range, it is advantageous to ensure dispersibility and maintain dispersibility in a dispersion solvent, and thereby, a composite material exhibiting uniform electrical conductivity can be manufactured.

The term average particle diameter used in this application is a so-called D50 particle diameter (median particle diameter), unless otherwise specified, and may mean a particle diameter at 50% cumulative volume basis of the particle size distribution. That is, the particle size distribution is obtained on a volume basis, and the particle diameter at the point where the cumulative value is 50% in the cumulative curve with the total volume as 100% can be seen as the average particle diameter. The D50 particle diameter as described above can be measured by a laser diffraction method.

In the method for manufacturing a composite material according to an example of the present application, the dispersing solvent may be used without particular limitation as long as it can disperse the insulating material, but considering that the insulating material is selected as a material favorable for nanowire formation, a polar solvent It is preferable to include

The polar solvent may include one or more selected from the group consisting of water, alcohol, and acid. The alcohol is methanol, ethanol, propanol, pentanol, octanol, ethylene glycol, propylene glycol, pentanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, glycerol, texanol, or A monohydric alcohol having 1 to 20 carbon atoms such as terpineol or a dihydric alcohol having 1 to 20 carbon atoms such as ethylene glycol, propylene glycol, hexanediol, octanediol or pentanediol or more polyhydric alcohols may be used. And, the acid (acid) is not limited to, for example, sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid or acetic acid can be used.

In the method for manufacturing a composite material according to an example of the present application, the insulating material dispersion contains 5% by weight or more, 5.5% by weight or more, 6% by weight or more, 6.5% by weight or more, 7% by weight or more, or 7.5% by weight or more based on the total weight of the insulating material. % or more, 8% by weight or more, 8.5% by weight or more, 9% by weight or more, 9.5% by weight or more, or 10% by weight or more. In another example, the insulating material dispersion contains, by weight, less than 40%, less than 39%, less than 38%, less than 37%, less than 36%, less than 35%, less than 34%, less than 33% by weight of the insulating material, by weight of the total weight. It may include less than 32% by weight, less than 31% by weight or less than 30% by weight. The content ratio of the insulating material may be within a range formed by appropriately selecting the above upper and lower limits. In addition, when the content ratio of the insulating material satisfies the above range, it is possible to form a nanowire capable of securing excellent electrical insulation while securing the dispersibility of the insulating material dispersion.

In the method for manufacturing a composite material according to an example of the present application, the insulating material dispersion is prepared by adding a dispersion solvent in an amount of 150 parts by weight or more, 175 parts by weight or more, 200 parts by weight or more, 225 parts by weight or more, or 250 parts by weight based on 100 parts by weight of the insulating material. Or more, 275 parts by weight or more, 300 parts by weight or more, 325 parts by weight or more, 350 parts by weight or more, 375 parts by weight or more, or 400 parts by weight or more. In another example, the insulating material dispersion includes 2,000 parts by weight or less, 1,800 parts by weight or less, 1,600 parts by weight or less, 1,400 parts by weight or less, 1,200 parts by weight or less, or 1,000 parts by weight or less, based on 100 parts by weight of the insulating material. can do. The content ratio of the dispersion solvent may be within a range formed by appropriately selecting the above upper and lower limits. In addition, when the content ratio of the dispersed material satisfies the above range, the dispersibility of the insulating material dispersion may be secured.

In the manufacturing method of the composite material according to an example of the present application, the heat treatment step is 800 ℃ or more, 820 ℃ or more, 840 ℃ or more, 860 ℃ or more, 880 ℃ or more, 900 ℃ or more, 920 ℃ or more, 940 ℃ or more, 960 ℃ Heat treatment may be performed at a heat treatment temperature of 980 °C or higher, or 1,000 °C or higher. In another example, the upper limit of the heat treatment temperature may be 2,000 °C or less, 1,800 °C or less, 1,600 °C or less, or 1,500 °C or less. The heat treatment temperature may be within a range formed by appropriately selecting the above upper and lower limits. In addition, when the heat treatment temperature satisfies the above range, nanowires can be effectively formed even in a large area.

In the method for manufacturing a composite material according to an example of the present application, the heat treatment may be performed with a heat treatment time of about 30 minutes, 40 minutes, 50 minutes, or 60 minutes while maintaining the heat treatment temperature. In another example, the heat treatment may be performed with a heat treatment time of about 500 minutes or less, 450 minutes or less, 400 minutes or less, 350 minutes or less, or 300 minutes or less while maintaining the heat treatment temperature. The heat treatment time may be within a range formed by appropriately selecting the above upper and lower limits.

In the method for manufacturing a composite material according to an example of the present application, the heat treatment step is 5 ℃ / min or more, 5.5 ℃ / min or more, 6 ℃ / min or more, 6.5 ℃ / min or more, 7 ℃ / min or more when the temperature is raised from room temperature to the heat treatment temperature. The temperature may be raised at a rate of °C/min or more, 7.5 °C/min or more, or 8 °C/min or more. In another example, the heat treatment step is 20 °C/min or less, 18 °C/min or less, 16 °C/min or less, 14 °C/min or less, 12 °C/min or less, or 10 °C/min when the temperature is raised from room temperature to the heat treatment temperature. The temperature can be raised at the following rate. The heating rate may be within a range formed by appropriately selecting the upper and lower limits described above.

In the method for manufacturing a composite material according to an example of the present application, the heat treatment may be performed in an environment containing hydrogen and an inert gas. When heat treatment is performed in an environment containing hydrogen and an inert gas, oxidation of silicon (Si) may be prevented by blocking oxygen. In particular, when heat treatment is performed in an oxygen environment, silicon (Si) is oxidized, which may be detrimental to the formation of nanowires.

Usage

An apparatus according to an example of the present application includes a heating element; and a cooling portion, and may include the composite material according to an example of the present application in which the heating element and the cooling portion are brought into thermal contact with each other.

Devices according to an example of the present application include, for example, an iron, a washing machine, a dryer, a clothes care machine, an electric shaver, a microwave oven, an electric oven, an electric rice cooker, a refrigerator, a dishwasher, an air conditioner, a fan, a humidifier, an air purifier, a mobile phone, and a walkie-talkie. , TVs, radios, computers, laptops, and other various electrical and electronic products, or batteries such as secondary batteries, and the composite material blocks current generated in electronic elements embedded in the device while dissipating heat generated in the device can make it

The composite can be placed between the exothermic element and the cooling section to bring them into thermal contact. Thermal contact means that the composite material directly physically contacts the exothermic element and the cooling part to dissipate heat generated from the exothermic element to the cooling part, or the composite material does not directly contact the exothermic element and/or the cooling part. (ie, a separate layer exists between the composite material and the exothermic element and/or the cooling part) means that the heat generated from the exothermic element is dissipated to the cooling part.

In addition, the composite material may be an electrical insulator that blocks current that may be generated in a heating element from being transferred to other components, and through this, generation of overcurrent or leakage of current may be blocked.

The composite material according to an example of the present application secures excellent heat dissipation characteristics and electrical insulation properties at the same time, thereby effectively dissipating heat generated in electronic components and the like, and blocking overcurrent or electric leakage.

The method for manufacturing a composite material according to an example of the present application has a simple process and can be manufactured in a large area.

1 is a diagram briefly showing the structure of a composite material according to an example of the present application.
Figure 2 shows a part of the nanowire layer of the composite prepared in Example 1 with a scanning electron microscope (SEM): (a) Magnification Х2,000 (b) Magnification Х27,000
3 is a scanning electron microscope (SEM) showing a part of the nanowire layer of the composite prepared in Example 6: (a) Magnification Х200 (b) Magnification Х5,000
4 is a scanning electron microscope (SEM) showing a part of the nanowire layer of the composite prepared in Example 9: (a) Magnification Х1,000 (b) Magnification Х10,000

Hereinafter, the present invention will be described through examples and comparative examples, but the scope of the present invention is not limited due to the contents presented below.

Example 1

An insulating material (A) containing silicon powder having an average particle diameter of about 500 nm and ethanol (E) were mixed in a weight ratio of 1:9 (A:E), and the mixture was mixed with ultrasonic waves and a mixer to about An insulating material dispersion was prepared by dispersing for 1 hour.

A copper metal form (about 70% porosity) cut into a width of 500 mm, length of 100 mm, and thickness of 100 μm was subjected to dip coating through the prepared insulating material dispersion, and after coating, sufficient moisture at room temperature dried until dry.

The copper metal foam coated with the insulating material dispersion was put into a sintering furnace, and a mixed gas containing hydrogen and argon was injected into the sintering furnace for about 1 hour to form the sintering furnace into an environment containing hydrogen and argon.

Thereafter, after raising the temperature from room temperature to about 1,000 ° C, which is the heat treatment temperature, at a temperature raising rate of 8 ° C / min, heat treatment was performed for about 5 hours while maintaining the heat treatment temperature. After the heat treatment was completed, the copper metal foam coated with the heat-treated insulating material dispersion was taken out of the firing furnace and sufficiently cooled at room temperature to prepare a final composite material including a nanowire layer. At this time, the thickness of the nanowire layer was about 3 to 4 μm.

In addition, FIG. 2 is a measurement of the nanowire layer with a scanning electron microscope (SEM), and it can be seen that the thickness of the nanowire is about 100 to 150 nm and the length is less than about 10 μm.

Example 2

A final composite was prepared in the same manner as in Example 1, except that heat treatment was performed for about 3 hours. At this time, the thickness of the nanowire layer was about 3 to 4 μm.

Example 3

A final composite was prepared in the same manner as in Example 1, except that heat treatment was performed for about 1 hour. At this time, the thickness of the nanowire layer was about 3 to 4 μm.

Example 4

An insulating material (A1) containing silicon powder having an average particle diameter of about 300 nm and ethanol (E) were mixed in a weight ratio of 1:9 (A:E), and the mixture was mixed with ultrasonic waves and a mixer to about A final composite material was prepared in the same manner as in Example 1, except that the insulating material dispersion was prepared by dispersing for 1 hour. At this time, the thickness of the nanowire layer was about 3 to 4 μm.

In addition, FIG. 3 is a measurement of the nanowire layer with a scanning electron microscope (SEM), and it can be seen that the nanowire has a thickness of about 30 to 70 nm and a length of about 10 μm or less.

Example 5

An insulating material (A1) containing silicon powder having an average particle diameter of about 1,000 nm and ethanol (E) were mixed in a weight ratio of 1:9 (A:E), and the mixture was mixed with ultrasonic waves and a mixer to about A final composite material was prepared in the same manner as in Example 1, except that the insulating material dispersion was prepared by dispersing for 1 hour. At this time, the thickness of the nanowire layer was about 3 to 4 μm.

Example 6

An insulating material (A1) containing silicon powder having an average particle diameter of about 500 nm and ethanol (E) were mixed in a weight ratio of 1:4 (A:E), and the mixture was mixed with ultrasonic waves and a mixer to about A final composite material was prepared in the same manner as in Example 1, except that the insulating material dispersion was prepared by dispersing for 1 hour. At this time, the thickness of the nanowire layer was about 10 μm.

Example 7

An insulating material (A1) containing silicon powder having an average particle diameter of about 500 nm and ethanol (E) were mixed in a weight ratio of 1:4 (A:E), and the mixture was mixed with ultrasonic waves and a mixer to about A final composite material was prepared in the same manner as in Example 1, except that an insulating material dispersion was prepared by dispersing for 1 hour and heat treatment was performed for about 3 hours. At this time, the thickness of the nanowire layer was about 10 μm.

Example 8

An insulating material (A1) containing silicon powder having an average particle diameter of about 500 nm and ethanol (E) were mixed in a weight ratio of 1:4 (A:E), and the mixture was mixed with ultrasonic waves and a mixer to about A final composite material was prepared in the same manner as in Example 1, except that an insulating material dispersion was prepared by dispersing for 1 hour and heat treatment was performed for about 1 hour. The thickness of the nanowire layer was about 10 µm.

Example 9

A final composite was prepared in the same manner as in Example 1, except that copper foil having a width of 50 mm, a length of 100 mm, and a thickness of 50 μm was used instead of the copper metal foam. The thickness of the nanowire layer was about 10 µm.

In addition, FIG. 3 is a measurement of the nanowire layer with a scanning electron microscope (SEM), and it can be seen that the nanowire has a thickness of about 30 to 70 nm and a length of about 10 μm or less.

Comparative Example 1

The copper metal foam prepared in Preparation Example 1 of the metal foam not including the nanowire layer was prepared.

Comparative Example 2

Silicon oxide (SiO ₂ ) powder (B) having an average particle diameter of about 1 μm and polydimethylsiloxane (supplier: DOW, product name: sylgard 527, PDMS) were mixed in a weight ratio of 1: 1 (B: PDMS), The mixture was dispersed for about 1 hour using ultrasonic waves and a mixer to prepare a silicon oxide dispersion.

The copper metal foam prepared in Metal Foam Preparation Example 1 was dip-coated on the prepared silicon oxide dispersion.

The coated copper metal form was put into an oven and cured by placing it at about 120° C. for about 30 minutes to prepare a final composite material including a silicon oxide coating layer. At this time, the thickness of the silicon oxide coating layer was 5 μm.

Physical properties presented in Examples and Comparative Examples were evaluated in the following manner.

<How to measure physical properties>

1. Sheet resistance measurement method

Sheet resistance was measured according to the 4 point probe sheet resistance measurement method for each composite material prepared in the above Examples and Comparative Examples. Specifically, four probes were arranged side by side at equal intervals of about 1 mm and mounted on the surface of the composite to measure sheet resistance.

2. Thermal diffusivity measurement method

For each of the composite materials prepared in the above Examples and Comparative Examples, the thermal diffusivity was measured in an in-plane direction according to the ASTM D4935 standard through a thermal diffusivity measuring device (Supplier: Netzsch, product name: LFA467).

The results of the test data measured in the above Examples and Comparative Examples are summarized in Table 1 below.

division Sheet resistance (mΩ/□) Thermal diffusivity (mm ² /s) Example 1 13 52 Example 2 12 52 Example 3 9 50 Example 4 12 51 Example 5 11 50 Example 6 20 51 Example 7 18 49 Example 8 17 50 Example 9 6 76 Comparative Example 1 0.8 60 Comparative Example 2 360 31

Referring to Table 1, it can be seen that Examples 1 to 9 have appropriate sheet resistance and secure excellent thermal diffusivity while securing electrical insulation.

On the other hand, it can be seen that Comparative Example 1 has an appropriate thermal diffusivity but low sheet resistance and electrical insulation is not secured, and Comparative Example 2 has an appropriate sheet resistance but low thermal diffusivity.

10: metal sheet 20: nano wire layer

Claims (20)

A metal sheet and a nanowire layer,
The nanowire layer includes one or more nanowires formed on at least one surface of the metal sheet. The method of claim 1, wherein the metal sheet is a composite material containing any one metal selected from the group consisting of copper, gold, silver, aluminum, nickel, iron, cobalt, magnesium, molybdenum, tungsten, and zinc, or an alloy of two or more of the above. . The composite according to claim 1, wherein the metal sheet is a metal foil or a metal foam. The composite material according to claim 1, wherein the ratio (L/D) of the thickness (D) to the length (L) of the at least one nano wire is 10 or more. The composite material according to claim 1, wherein the one or more nano wires have a thickness (D) in the range of 10 to 300 nm. The composite material according to claim 1, wherein the length (L) of one or more nano wires is in the range of 1 to 100 μm. The composite of claim 1 , wherein the one or more nano wires include an insulating material. The composite material according to claim 1, wherein the thickness of the nanowire layer is in the range of 1 to 20 μm. The composite according to claim 1, wherein the ratio (A2/A1) of the thickness of the metal sheet (A1) and the thickness of the nanowire layer (A2) is in the range of 0.001 to 10. The composite according to claim 1, wherein the sheet resistance is 1 mΩ/□ or more, and the thermal diffusivity according to ASTM D4935 is 35 mm ² /s or more. coating an insulating material dispersion on at least one surface of the metal sheet; and
Heat-treating the metal sheet coated with the insulating material dispersion,
Wherein the coating step is performed by at least one selected from the group consisting of dip coating, blade coating and spin coating. 12. The method of claim 11, wherein the insulating material dispersion comprises an insulating material and a dispersing solvent,
The average particle diameter of the insulating material is a method for producing a composite material having a range of 100 to 2,000 nm. 13. The method of claim 12, wherein the insulating material includes silicon (Si) powder. 13. The method of claim 12, wherein the dispersing solvent includes a polar solvent. 13. The method of claim 12, wherein the insulating material dispersion includes the insulating material in a range of 5 to 40% by weight based on the total weight. The method of claim 11, wherein the heat treatment is performed at a heat treatment temperature of 800 °C or higher. The method of claim 16, wherein the heat treatment step is performed with a heat treatment time in the range of 30 to 500 minutes while maintaining the heat treatment temperature. The method of claim 16, wherein the heat treatment step is performed at a rate of 5 to 20 °C/min when the temperature is raised from room temperature to the heat treatment temperature. The method of claim 11, wherein the heat treatment is performed in an environment containing hydrogen and an inert gas. exothermic element; and a cooling portion;
A device comprising the composite material according to claim 1 between and in thermal contact with the exothermic element and the cooling section.

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