WO2023287222A1

WO2023287222A1 - Method for preparing low-density plate-shaped conductive powder

Info

Publication number: WO2023287222A1
Application number: PCT/KR2022/010288
Authority: WO
Inventors: 김태엽; 조상호
Original assignee: 엑시노 주식회사
Priority date: 2021-07-16
Filing date: 2022-07-14
Publication date: 2023-01-19
Also published as: KR20230012896A

Abstract

A method for preparing low-density plate-shaped conductive powder is disclosed. The preparation method according to one embodiment comprises the steps of: preparing polymer powder; forming the prepared polymer powder into a plate shape by mechanically milling same; and coating metal on the surface of the polymer powder which has been formed into a plate shape in the plate-shape forming step.

Description

Manufacturing method of low-density plate-shaped conductive powder

The present invention relates to a low-density conductive powder, and more particularly, to a flat low-density polymer powder and a method for manufacturing the conductive powder including the same.

With the advancement of information and communication technology, portable electronic devices are continuously being made lighter and smaller. For example, a tablet computer or a notebook computer, including a smart phone, is gradually becoming lighter in weight and thinner in spite of increasingly high functionality and high specifications. To this end, research and development on materials that can support light-thin and short-circuiting for the main body of the product as well as internal electronic components, adhesives or films for bonding or mounting them are continuously being pursued.

Among various technological factors for realizing light, thin, and compact portable electronic devices, the importance of a conductive adhesive material for mounting and bonding electronic components such as highly integrated IC chips on a circuit board is continuously increasing. Due to the nature of these conductive adhesives used in electronic devices, not only high conductivity is required, but also performance such as thermal conductivity and formability along with electromagnetic wave shielding ability is required. In particular, in order to support thin, thin and short electronic devices, the importance of low-density characteristics such as conductive adhesives and conductive films is gradually increasing.

In general, a conductive adhesive or conductive film is manufactured by molding a paste or mixture of a metal powder having high electrical conductivity, such as silver, copper, nickel, or zinc, with an organic binder (synthetic resin), into a film form. However, metal powder is basically a material with high density, so there is a limit to weight reduction, and dispersion stability is poor, as well as stability over time, so when precipitation occurs over time, there is a problem of poor uniformity. Due to this, the thickness of the conductive adhesive or the conductive film is non-uniform, the surface is rough, and the conductive properties are not satisfied locally.

In order to solve the disadvantages of these metal powders, various methods have been proposed. For example, a method of lowering the density by manufacturing a hollow metal powder or using a plastic ball instead of a metal powder has been proposed. In the latter case, by applying electroless metal plating to the surface of a plastic ball made of, for example, PolyStyrene (PS), PolyMethyl MethAcrylate (PMMA), Arcylonitrile Butadiene Styrene (ABS), PolyOxy Methylene (POM), PolyAcryloNitrile (PAN), etc. Low density is achieved while maintaining conductivity.

However, in the conventional method of plating metal on plastic balls, low density of the powder is possible by using a base material core material with low density, but the shape of the particles is spherical and the contact between the particles becomes a point contact to realize high conductivity. There are limits.

[Prior art literature]

(Patent Document 1) Korean Patent Registration No. 10-1718158

(Patent Document 2) Korea Patent Registration No. 10-1343997

(Patent Document 3) Korean Patent Publication No. 10-2020-0113461

One problem to be solved by the present invention is a low-density plate-like polymer powder capable of preparing a spherical or amorphous polymer powder in a plate-like shape with a wide contact area between particles so as to manufacture a low-density conductive powder capable of implementing high conductivity. It is to provide a manufacturing method of.

Another problem to be solved by the present invention is to provide a method for producing a plate-shaped low-density and conductive powder capable of implementing high conductivity and reducing density.

A method for manufacturing a low-density plate-shaped conductive powder according to an embodiment of the present invention for solving the above problems includes preparing a polymer powder, mechanically milling the prepared polymer powder to make it plate-shaped, and the plate-shaped conductive powder. A step of coating a metal on the surface of the planarized polymer powder in the phase forming step.

According to one aspect of the embodiment, the polymer powder is polyacrylonitrile (PolyAcryloNitrile, PAN), polymethyl methacrylate (PolyMetahyl MethAcrylate, PMMA), polystyrene (PolyStyrene, PS), polyethylene (PolyEthylene, PE) and It may be formed of one or more copolymers selected from the group consisting of polypropylene (PP).

According to another aspect of the embodiment, the polymer powder may have a spherical or amorphous shape with an average particle diameter of 1 to 60 μm.

Further, the plate-shaped polymer powder produced as a result of the plate-forming step has a length of a long axis of 2 to 150 μm and a thickness of 0.2 to 2 μm, and a ratio of the length of the long axis to the thickness may be 10 to 300.

In the plate-forming step, the prepared polymer powder may be mechanically milled using one or more methods selected from among a ball mill method, an attrition mill method, and a beads mill method. In this case, in the plate-forming step, in order to increase the effect of mixing and dispersing the polymer powder, a solvent may be included during the process, and the solvent is methanol, ethanol, 1,2-propanol (1 , 2-Propanol), ethylene glycol, glycerol, and the like. At least one kind may be selected from alcohols. In addition, depending on the type of polymer powder, mechanical milling may be performed at a temperature higher than room temperature in order to increase the milling effect.

According to another aspect of the embodiment, the metal is silver (Ag), copper (Cu), nickel (Ni), tin (Sn), gold (Au), aluminum (Al), bismuth (Bi), iron (Fe ) and cobalt (Co), or any one or two or more alloys selected from the group consisting of. In this case, in the metal coating step, a single metal layer or multiple metal layers may be formed on the surface of the plate-shaped polymer powder.

According to the above-described embodiments of the present invention, the spherical or amorphous polymer powder can be easily and inexpensively manufactured into a plate-like shape having a desired thickness-to-diameter (or major axis length). In addition, by coating the prepared plate-like polymer powder with a metal, it can be used to manufacture a conductive powder having excellent conductivity and low density. At this time, since plate-shaped powder having a large planar area rather than a spherical three-dimensional shape is used as the conductive particle, the contact area between the powders increases and high conductivity can be realized.

1 is a flowchart showing a method of manufacturing low-density plate-like conductive powder according to an embodiment of the present invention.

2A is a diagram schematically showing a case in which a single metal layer is formed on the surface of a plate-like polymer powder.

2B is a diagram schematically showing a case in which two metal layers are formed on the surface of a plate-like polymer powder.

3a and 3b are SEM images of the prepared spherical polymer powder, and FIG. 3b is an enlarged portion of FIG. 3a.

4a and 4b are SEM images of plate-shaped polymer powder prepared according to an experimental example, and FIG. 4b is an enlarged portion of FIG. 4a.

5a and 5b are SEM images of copper (Cu)-coated plate-like polymer powder prepared according to Experimental Example 2, and FIG. 5b is an enlarged view of a portion of FIG. 5a.

6a and 6b are SEM images of plate-like polymer powder coated with nickel (Ni) prepared according to Experimental Example 3, and FIG. 6b is an enlarged view of a portion of FIG. 6a.

7A and 7B are SEM pictures of plate-shaped polymer powder prepared by coating copper (Cu) as a first coating layer and then coating silver (Ag) as a second coating layer according to Experimental Example 4, and FIG. 7B is a portion of FIG. 7A It shows enlarged.

8A to 8C show EDS mapping pictures of platelet polymer powders sequentially coated with silver (Ag) and copper (Cu) prepared according to Experimental Example 4, and FIG. 8B shows copper in FIG. 8A ( It shows the distribution of Cu), and FIG. 8c is a photograph showing the distribution of silver (Ag) in FIG. 8a.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Terms and words used in this specification are terms selected in consideration of functions in the embodiments, and the meanings of the terms may vary depending on the intention or practice of the invention. Therefore, the terms used in the embodiments to be described later, when specifically defined in the present specification, follow the definition, and when there is no specific definition, they should be interpreted as meanings generally recognized by those skilled in the art.

A method for manufacturing a plate-shaped, low-density conductive powder according to an embodiment of the present invention includes, first, a process of preparing a polymer powder in a plate-like shape (plate-shaped process of polymer powder), and a process of coating the plate-shaped polymer powder with a metal. (coating process of plate-like polymer powder). Here, the 'coating process' is generally performed using the plate-shaped polymer powder produced as a result of the 'plate-forming process' according to an embodiment of the present invention described later, but is not limited thereto. For example, the coating process may be performed using a plate-shaped polymer powder prepared using a method other than the examples described below.

Referring to FIG. 1, first, a polymer powder to be plated is prepared (S10). There is no particular limitation on the type of polymer powder. For example, the polymer powder is polyacrylonitrile (PolyAcryloNitrile, PAN), polymethyl methacrylate (PolyMetahyl MethAcrylate, PMMA), polystyrene (PS), polyethylene (PolyEthylene, PE) and polypropylene (PolyPropylene, PP). It may be one copolymer selected from the group consisting of, or a mixture in which two or more copolymers are mixed. Preferably, the polymer powder is polyacrylonitrile. Polyacrylonicryl polymer powder has excellent ductility compared to other types of polymer powder and is easier to plate.

And the prepared polymer powder has a three-dimensional shape, such as a spherical or amorphous shape. For example, when the spherical polymer powder is plate-shaped by mechanical milling in step S20 to be described later, it has a circular or elliptical shape with a thin thickness, so it is easy to control the shape of the powder even if it is plate-shaped. In addition, when coated with metal, a wider contact area can be secured between circular or elliptical powders, and there is an advantage in that the deviation of the contact area between the powders is small.

For example, the spherical polymer powder may have an average particle diameter of 1 μm to 60 μm. Preferably, the polymer powder preferably has an average particle diameter of 3 to 15 μm. When the average particle diameter of the polymer powder is smaller than 3 μm, it is not easy to coat the polymer with metal even if it is plate-shaped, and it is difficult to secure a large contact area between the powders. On the other hand, when the average particle diameter of the polymer powder is greater than 15 μm, the particle size greatly increases after plate-shaping, making it difficult to evenly distribute the powder during manufacture of pastes or films, as well as making it difficult to thin and refine the product.

Subsequently, the prepared polymer powder is mechanically milled to plate it (S20). Here, "mechanical milling" refers to flattening by physically applying impact and/or pressure to polymer powder using a milling machine commonly used to make fine powder. In general, metal particles, paints, grains, etc. are broken into smaller particles (powder) when using a milling machine. However, in the case of a polymer powder, its shape is easily deformed rather than split into smaller sizes even when an impact or pressure is applied due to its material properties (eg, ductility). More specifically, in the case of spherical polymer powder, when mechanical milling is performed using a milling machine, it can be flattened by impact or pressure and plated into a circular or elliptical shape.

Here, there is no particular limitation on the type of milling machine for performing mechanical milling. For example, the milling machine may be a device for mechanically milling using one or more methods selected from among a ball mill method, an attrition mill method, and a beads mill method. Depending on the milling conditions such as the size of the ball used, the rotational speed, and the processing time, the milling device (ie, the milling method used in the milling machine) can be selectively used. According to an embodiment of the present invention, it is preferable to perform the plate forming step (S20) using the attrition mill method in consideration of the ball size, rotational speed, productivity, and the like.

According to an embodiment of the present invention, the mechanical milling in step S20 is preferably performed in a state in which the polymer powder is dispersed in a predetermined solvent. When the polymer powder is dispersed in a solvent, mixing and dispersing effects of the polymer powder can be enhanced, and more uniform milling is possible. Since the polymer powder is hydrophobic and has a lower density than water, it does not disperse well in water. Therefore, it is preferable to use an organic solvent instead of water for dispersing the polymer powder. However, when an organic solvent is used as a dispersion, the polymer powder may be dissolved depending on its type, so an organic solvent of a type in which the polymer powder does not dissolve well should be used.

More specifically, polymer powders such as polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), polystyrene (PS), polyethylene (PE) or polypropylene (PP) are not easily soluble in alcohol. Therefore, the organic solvent used in the mechanical milling process in step S20 is preferably alcohol. For example, the alcoholic organic solvent may be methanol, ethanol, 1,2-propanol, ethylene glycol, glycerol, or a mixture thereof. can In this case, since the polymer powder is not easily dissolved in the organic solvent and is uniformly dispersed, it is possible to plate the particle size uniformly without damaging the polymer powder.

However, since the above-mentioned polymer powder can be easily dissolved in ketones (e.g., acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, etc.) It is preferable not to use it as a solvent. If ketones are used as a solvent, the polymer powder is dissolved and the base material may be damaged when the milling machine is used for a long time.

According to one embodiment of the present invention, the mechanical milling process of step S20 may be performed at a temperature of 10° C. or higher, but the temperature should be lower than the boiling point of the solvent used. In this case, depending on the type of polymer powder, it is preferable to perform the milling at a temperature higher than room temperature (25° C.) in order to increase the milling effect. For example, high-strength polymer powders such as polymethyl methacrylate (PMMA) have low ductility and can easily break the powder during mechanical milling. Therefore, the temperature is maintained high during the milling process to increase the ductility of the powder, thereby increasing the platelet efficiency. can increase In this case, the mechanical milling process is preferably performed at room temperature lower than the boiling point of the organic solvent, for example, 25 to 75°C. If the process temperature is less than 25 ° C., the ductility of the polymer powder is not increased, so the polymer powder can be easily broken. On the other hand, when the process temperature is 75° C. or higher, it may be difficult to perform the milling process for a long time because the solvent is evaporated and the amount is reduced during the mechanical milling process.

In addition, it is preferable to perform this mechanical milling process at a predetermined rotational speed (rpm) for a predetermined time so that more powder can be plated. For example, the mechanical milling process is preferably performed at 200 to 600 rpm for about 10 to 60 minutes. When the rotational speed is too small or the process time is too short, there is a concern that only a part of the polymer powder introduced is plated. On the other hand, if the rotation speed is too high, there is a concern that the polymer powder is not plated and pulverized, and if the process time is too long, not only is it a factor that lowers productivity, but also the polymer powder is dissolved in an organic solvent. There is a risk that this may be damaged.

And the size of the ball used in the mechanical milling process is 0.5 to 4mm, preferably 1 to 3mm. If the size of the ball is too small (for example, 1 mm or less), it is difficult to flatten the polymer powder as a whole and it is easy to break the polymer powder due to partial impact. On the other hand, if the size of the ball is too large (eg, 4 mm or more), the impact applied by the ball is great, so the polymer powder is also easy to break.

As such, in step S20, when the plate-forming process is performed on the polymer powder using a mechanical milling method under predetermined process conditions (ie, the above-described process temperature, rotational speed, and/or ball size, etc.), the spherical polymer powder The silver is plated to form a plate-like polymer powder. For example, when spherical polymer powder having an average particle diameter of 1 to 60 μm is plated using a ball mill method, a bead mill method, or an attrition mill method, the length of the long axis (or diameter) is 2 to 150 μm and the thickness is 0.2 μm. As ~2 μm, a platelet polymer powder with a length to thickness ratio of 10 to 300 can be made.

Continuing to refer to FIG. 1 , a conductive metal material is coated on the surface of the planarized polymer powder in the planarization process of step S20 (S30). Here, the metal to be coated is silver (Ag), copper (Cu), nickel (Ni), tin (Sn), gold (Au), aluminum (Al), bismuth (Bi), iron (Fe) or cobalt (Co) may be a single metal or a mixture of two or more metals among them.

According to one aspect of this embodiment, there is no particular limitation on the method of coating the surface of the plate-like polymer powder with a conductive metal material, and any known technique for coating the polymer powder with a metal material may be used. For example, according to the method disclosed in Patent Document 1 (Korean Patent Registration No. 10-1718158) or Patent Document 3 (Korean Patent Publication No. 10-2020-0113461), metal is deposited on the surface of the plate-shaped polymer powder by electroless plating. The material may be coated.

According to another aspect of this embodiment, in the coating process of step S30, a predetermined coating solution containing metal ions to be coated is prepared, plated polymer powder is introduced into the prepared coating solution, and then for a predetermined period of time. By stirring the solution, the surface of the polymer powder may be coated with the corresponding metal material. To this end, the coating solution includes a complexing agent and a reducing agent together with metal ions (metal precursors) so that metal ions can be bound to the surface of the polymer powder by a redox reaction during stirring. Here, the complexing agent serves to form a complex compound of metal ions. Since the produced metal complex has a lower redox potential than pure metal ions, a rapid reduction reaction of metal ions is suppressed to form a uniform metal coating layer.

And, if necessary, the coating solution may further contain a pH adjuster so that the oxidation-reduction reaction can occur smoothly by the reducing agent. According to one embodiment of the present invention, the hydrogen ion concentration (pH) of the coating solution is preferably 7 or more and 12 or less. If the hydrogen ion concentration of the coating solution is less than 7, stability of the solution is lowered and complexes of metal ions may be precipitated. On the other hand, when the hydrogen ion concentration of the coating solution is greater than 12, the speed of the oxidation-reduction reaction is too fast, and the coating layer may be non-uniform.

And according to an embodiment of the present invention, in the metal coating step of step S30, a single metal layer or multiple metal layers may be formed on the surface of the polymer powder. In the latter case, the multiple metal layers need not necessarily be of the same kind of metal, but may be of different kinds of metal. 2A and 2B are views schematically showing a case in which a single metal layer 4 or two

metal layers

6a and 6b are formed on the surface of the plate-like polymer powder 2 in step S30, respectively. .

The plate-shaped low-density conductive powder prepared according to the embodiment of the present invention has a significantly lower density than the conventional metal conductive powder. For example, in the case of silver (Ag), the density is 10.49 g / cm3, in the case of copper (Cu), the density is 8.93 g / cm3, in the case of nickel (Ni), the density is 8.8 g / cm3, etc., but the result of step S30 The conductive powder made of (conductive powder in FIG. 2A) has a tap density of 2.5 g/cm3 or less regardless of the type of metal 4 coated on the surface of the plate-like polymer powder 2.

In addition, the plate-shaped low-density conductive powder prepared according to the embodiment of the present invention can be mixed with a polymer resin to be prepared in the form of a conductive paste, film, or sheet, and the plate-shaped low-density conductive powder prepared according to the embodiment itself or mixed with other conductive powders and can be used.

Hereinafter, experimental examples according to the above-described embodiments of the present invention will be described. However, the experimental examples described below are intended to specifically illustrate or explain the above-described embodiments of the present invention, and the embodiments of the present invention are not limited by the experimental examples described later.

Experimental Example 1

Experimental Example 1 is an example of a process of plate-forming polymer powder. More specifically, first, a spherical polymer powder having a particle diameter of 3 to 15 μm is prepared. 3a and 3b are SEM images of an example of the prepared spherical polymer powder, and FIG. 3b is an enlarged portion of FIG. 3a. Then, a ball with a diameter of 1 to 3 mm is put into the stirrer of the attrition milling device, and then ethanol and polymer powder are mixed at a weight ratio of 10: 1 (eg, 200 g of ethanol and 20 g of polymer powder), It is put into the agitator of the milling device. Subsequently, the stirrer is rotated to plate the polymer powder. In this experimental example, milling was performed at 200 rpm, 400 rpm, or 600 rpm for 10 minutes, 20 minutes, 40 minutes, or 60 minutes, respectively, to prepare a plate-shaped polymer powder having a powder size (long axis length of the plate-shaped powder) of 10 to 20 μm. Figures 4a and 4b are SEM pictures of the plated polymer powder prepared according to the process conditions of item 3 of Table 1 below, and Figure 4b is an enlarged portion of Figure 4a.

Table 1 shows the process conditions used in the plate-forming process of Experimental Example 1, that is, the diameter of the polymer powder (polymer size), the size of the ball (ball size), the rotation speed of the stirrer (milling speed) and the plate-forming process time (milling time). ), it shows a comparison of the process conditions and the results of particle size analysis (PSA, Particle Size Analysis) of the plated polymer powder according to the experiment while changing some of them. In Table 1, the particle sizes corresponding to 10%, 50%, and 90% of the volume accumulation from the smaller particle size side in the particle size distribution are indicated as D10, D50, and D90, respectively. And the item Span is a value of (D90-D10)/D50, showing the degree of uniformity of the size distribution of the polymer powder.

Referring to Table 1, it can be seen that as the ball size and milling time increase, the polymer particles are plated and the size of the particles (eg, the size corresponding to the particle size D50) increases. In addition, as the size of the ball increases, the size of the particle increases, but the uniformity (span) of the particle decreases, and damage may occur to the outer portion of the plate-shaped polymer particle. In addition, when the ball size, rotation speed, and milling time are too large, for example, when the ball size is 4 μm or more (eg, 5 μm) and / or the rotation speed exceeds 600 rpm (eg, 800 rpm), The polymer particles are broken, making it difficult to plate them.

Experimental Example 2

Experimental Example 2 is an example of a process of coating copper (Cu) as an example of a conductive metal on the surface of a plate-shaped polymer powder using a redox reaction. More specifically, first, 10 g of plate-like polymer powder is prepared. The plate-like polymer powder may be prepared according to Experimental Example 1 described above, but is not limited thereto. And prepare a coating solution by mixing 70g of metal salt CuSO4·5H2O, 68g of complexing agent KNaC4H4O6·4H2O, 55g of Hydrazine as reducing agent, and 50g of NaOH as pH adjusting agent in 1L of distilled water. Subsequently, the prepared plate-like polymer powder is added to the coating solution while the temperature is maintained at 50° C. and stirred for 30 minutes, so that copper (Cu) is bonded to the surface of the plate-like polymer powder. Thereafter, the powder coated with copper (Cu) is washed and then dried in an oven.

Experimental Example 3

Experimental Example 3 is an example of a process of coating nickel (Ni) as an example of a conductive metal on the surface of a plate-shaped polymer powder using a redox reaction. More specifically, first, 10 g of plate-like polymer powder is prepared. The plate-shaped polymer powder may be prepared according to Experimental Example 1 described above, but is not limited thereto. In addition, a coating solution was prepared by mixing 75 g of metal salt NiCl6 6H2O, 80 g of complexing agent K3C6H5O7, 60 g of reducing agent Hydrazine, and 45 g of pH adjusting agent NaOH in 1 L of distilled water. Subsequently, the prepared plate-like polymer powder is added to the coating solution while maintaining the temperature at 60° C. and stirred for 30 minutes, so that nickel (Ni) is bonded to the surface of the plate-like polymer powder. Thereafter, the powder coated with nickel (Ni) is washed and then dried in an oven.

Experimental Example 4

Experimental Example 4 is an example of a process of additionally coating silver (Ag) as an example of a conductive metal on the surface of the plate-shaped polymer powder coated with copper (Cu) of Experimental Example 2. More specifically, first, 10 g of plate-like polymer powder coated with copper is prepared. The plate-shaped polymer powder coated with copper may be prepared according to Experimental Example 2 described above, but is not limited thereto. Then, a coating solution was prepared by mixing 30 g of metal salt AgNO3, 70 g of complexing agent NH4OH, 91 g of reducing agent C6H8O6, and 20 g of pH adjusting agent NaOH in 1 L of distilled water. Subsequently, the prepared plate-like polymer powder is added to the coating solution while the temperature is maintained at 10° C. and stirred for 30 minutes, so that silver (Ag) is bonded to the surface of the plate-like polymer powder. Thereafter, the powder coated with silver (Ag) is washed and then dried in an oven.

7a and 7b are SEM images of a plate-like polymer powder sequentially coated with multiple layers of copper (Cu) and silver (Ag) prepared according to Experimental Example 4, and FIG. 7b is an enlarged view of a portion of FIG. 7a.

8a to 8c are EDS (Energy Dispersive x-ray Spectrometer) mapping photographs of the plate-shaped polymer powder sequentially coated with copper (Cu) and silver (Ag) in multiple layers prepared according to Experimental Example 4 As shown, FIG. 8b shows the distribution of copper (Cu) in FIG. 8a, and FIG. 8c is a photograph showing the distribution of silver (Ag) in FIG. 8a. 8a to 8c, even if copper (Cu) and silver (Ag) are sequentially coated on the polymer powder, it can be seen that both copper (Cu) and silver (Ag) are uniformly coated because the overall distribution is similar. .

Although the present invention has been described in detail with preferred embodiments, the present invention is not limited to the above-described embodiments, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. It is possible.

The low-density plate-like conductive powder manufactured according to the present invention can be used for manufacturing a highly reliable conductive adhesive or conductive film.

Claims

preparing polymer powder;

mechanically milling the prepared polymer powder into a plate; and

Method for producing a low-density plate-like conductive powder comprising the step of coating a metal on the surface of the plate-shaped polymer powder in the plate-shaped step.
According to claim 1,

The polymer powder is polyacrylonitrile (PolyAcryloNitrile, PAN), polymethyl methacrylate (PolyMetahyl MethAcrylate, PMMA), polystyrene (PS), polyethylene (PolyEthylene, PE) and polypropylene (PolyPropylene, PP). A method for producing a low-density plate-shaped conductive powder, characterized in that it is formed of at least one copolymer selected from the group consisting of.
According to claim 1 or 2,

The method for producing a low-density plate-like conductive powder, characterized in that the polymer powder has a spherical or amorphous shape with an average particle diameter of 1 to 60 μm.
According to claim 1 or 2,

The plate-shaped polymer powder produced as a result of the plate-forming step has a length of a long axis of 2 to 150 μm and a thickness of 0.2 to 2 μm, and a ratio of the length of the long axis to the thickness is 10 to 300. Method for producing low-density plate-shaped conductive powder.
According to claim 1 or 2,

The plate-forming step is characterized by mechanically milling the prepared polymer powder using at least one method selected from a ball mill method, an attrition mill method and a beads mill method Method for producing low-density plate-shaped conductive powder.
According to claim 5,

The plate-forming step is one selected from alcohols including methanol, ethanol, 1,2-propanol, ethylene glycol and glycerol A method for producing a low-density plate-like conductive powder, characterized in that mechanical milling is performed in a state in which the prepared polymer powder is dispersed in the above solvent.
According to claim 1,

The metal is a group consisting of silver (Ag), copper (Cu), nickel (Ni), tin (Sn), gold (Au), aluminum (Al), bismuth (Bi), iron (Fe) and cobalt (Co) Method for producing a low-density plate-shaped conductive powder, characterized in that consisting of any one or two or more alloys selected from.
According to claim 7,

In the metal coating step, a single metal layer or a multi-layer metal layer is formed on the surface of the plate-shaped polymer powder.
According to claim 1,

The method of manufacturing a low-density plate-like conductive powder, characterized in that the conductive powder produced as a result of the metal coating step has a tap density of 2.5 g / cm3 or less.