KR101828311B1 - Sputtering method for a electrical conductive particle, and electrical conductive particle formed by the same - Google Patents

Abstract

According to one embodiment of the present invention, disclosed is a sputtering method for an electrical conductive particle, comprising steps of: installing a target having an electrical conductive material to face a container containing powder of a plurality of insulating particles; forming an electrical conductive film in each of the insulating particles by striking the target under the inert gas atmosphere; and mixing or stirring the powder in the container.

Description

[0001] The present invention relates to a method of sputtering conductive particles and a conductive particle formed by the method,

Embodiments of the present invention relate to a method of sputtering conductive particles and conductive particles formed by the method.

In order to electrically connect the pad on the substrate and the flexible printed circuit board, such as a display device, materials such as anisotropic conductive paste and anisotropic conductive film are used. Such anisotropic conductive material includes conductive particles dispersed in a binder.

As the area of the electrodes connected through the anisotropic conductive material and the interval between the electrodes gradually become narrower, the specifications required for the conductive particles are also gradually increasing.

Specifications required for conductive particles, high conductivity, and durability such that cracks do not occur during the bonding process. Embodiments of the present invention provide a method for sputtering conductive particles and a conductive particle formed by the method for solving various problems including the above-mentioned problems.

The above-described problems are illustrative, and thus the scope of the present invention is not limited thereto.

An embodiment of the present invention provides a method of manufacturing a semiconductor device, comprising: providing a target including a conductive material so as to face a container containing a powder of a plurality of insulating particles; Forming a conductive coating on each of the plurality of insulating particles by blowing the target in an inert gas atmosphere; And a step of mixing or stirring the powder in the vessel.

In the present embodiment, the mixing or stirring process may be performed during the process of forming the conductive film.

In the present embodiment, the mixing or stirring step may include a step of rotating at least a part of the separator contained in the powder relative to the container.

In this embodiment, the separator may include at least one of a plurality of pins spaced apart from each other, and a plate extended to have a predetermined area along an oblique direction with respect to a bottom surface of the container.

In the present embodiment, the mixing or stirring step may include a step of vibrating the container.

In the present embodiment, the step of forming the conductive coating may include the steps of: forming a first conductive coating on each of the plurality of insulating particles using a first target containing a first conductive material; And forming a second conductive coating on the first conductive coating using a second target comprising a second conductive material different from the first conductive material.

In the present embodiment, the step of forming the first conductive coating and the step of forming the second conductive coating may be successively performed in the same chamber and under substantially the same pressure.

In the present embodiment, the first conductive material may include copper, and the second conductive material may include at least one of nickel, chromium, and alloys thereof.

In the present embodiment, the step of forming the conductive coating may form a single layer of the conductive coating using a target containing a metallic material.

In this embodiment, the metallic material may include silver.

In the present embodiment, it is possible to further include a step of applying heat to the container.

In the present embodiment, the insulating particles may include a resin.

In the present embodiment, the resin may include an acrylic resin.

Another embodiment of the present invention includes the conductive particles produced by the above-described process.

Other aspects, features, and advantages will become apparent from the following drawings, claims, and detailed description of the invention.

According to the embodiments of the present invention, it is possible to provide a large amount of conductive particles having excellent durability and excellent conductivity as well as having high resistance to cracking. Of course, the scope of the present invention is not limited by these effects.

1 is a front view schematically showing conductive particles according to an embodiment of the present invention.
2A is a cross-sectional view of a conductive particle according to an embodiment of the present invention.
2B is a cross-sectional view of a conductive particle according to another embodiment of the present invention.
3 is a cross-sectional view schematically showing a sputtering apparatus according to an embodiment of the present invention.
Fig. 4 is a perspective view showing the container and separator taken in Fig. 3; Fig.
FIG. 5 is a side view of a portion of the separator of FIG. 4 taken partially. FIG.
6 is a flowchart schematically showing a sputtering process of conductive particles according to an embodiment of the present invention.
7 is a flowchart schematically showing a sputtering process of conductive particles according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention and methods of achieving them will be apparent with reference to the embodiments described in detail below with reference to the drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or corresponding components throughout the drawings, and a duplicate description thereof will be omitted .

In the following embodiments, the terms first, second, and the like are used for the purpose of distinguishing one element from another element, not the limitative meaning.

In the following examples, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

In the following embodiments, terms such as inclusive or possessive are intended to mean that a feature, or element, described in the specification is present, and does not preclude the possibility that one or more other features or elements may be added.

In the drawings, components may be exaggerated or reduced in size for convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and thus the present invention is not necessarily limited to those shown in the drawings.

If certain embodiments are otherwise feasible, the particular process sequence may be performed differently from the sequence described. For example, two processes that are described in succession may be performed substantially concurrently, and may be performed in the reverse order of the order described.

Conductive particle

2 is a cross-sectional view of a conductive particle according to an embodiment of the present invention. FIG. 2B is a cross-sectional view of a conductive particle according to another embodiment of the present invention. Fig.

1, 2A and 2B, the conductive particles 10 include an insulating core 11 and a shell 13 covering the surface of the insulating core 11 and containing a conductive material.

The insulating core 11 is a spherical core and includes an electrically insulating material. The electrically insulating material may include an insulating resin. The insulating resin may be at least one resin selected from the group consisting of polymethyl methacrylate (PMMA), acrylic resin such as polymethyl acrylate, silicone resin such as polysiloxane, and polyolefin resin such as polyethylene, polypropylene and polystyrene . In yet another embodiment, the insulating resin is selected from the group consisting of polycarbonate, polysulfone, polybutylene, polyester, polyurethane, styrene butadiene, polyethersulfone, polyvinyl butyral, polyvinyl formal, polyvinylacetate, styrene divinyl benzene , An epoxy resin, and a phenol resin.

In one embodiment, the insulating core 11 may be made of polymethylmethacrylate (PMMA).

The shell 13 comprises a conductive material. The conductive material may include a metallic material. The metallic material may be selected from the group consisting of copper (Cu), nickel (Ni), chromium (Cr), silver (Ag), gold (Au), aluminum (Al), palladium (Pd), titanium (Ti), tin Mo), and an alloy thereof.

In one embodiment, the shell 13 may be formed as a single layer directly on the outer surface of the insulating core 11 as shown in FIG. 2A. The shell 13 may include a metallic material having excellent conductivity, heat resistance and corrosion resistance, such as silver (Ag).

In another embodiment, the shell 13 includes a first shell 13a directly on the outer surface of the insulating core 11 and a second shell 13b located on the first shell 13a, (13b). The first shell 13a is made of, for example, copper (Cu), and the second shell 13b is made of, for example, an alloy of nickel (Ni) and chromium (Cr) .

The conductive particles 10 may have a substantially smooth outer surface. The shortest distance d2a from the arbitrary point on the outer surface of the shell 13 to the surface of the insulating core 11 and the shortest distance d2a from the arbitrary point on the outer surface of the shell 13 to the surface of the insulating core 11 The distance d2b may be substantially the same. The shortest distance d2a from the arbitrary point on the outer surface of the shell 13 to the surface of the insulating core 11 and the surface of the insulating core 11 from any other point on the outer surface of the shell 13 May be in a range of 0 占 퐉 to 1 占 퐉, for example, 0 占 퐉 to 0.1 占 퐉, and as another example, 0 占 퐉 to 0.01 占 퐉. In other words, the deviation between the thicknesses measured at any point of the shell 13 may range from about 0 탆 to 1 탆, for example, from 0 탆 to 0.1 탆, as another example, from 0 탆 to 0.01 탆, As shown in FIG.

The conductive particles 10 of the embodiments as described above may be formed of a conductive filler or a shell having a large surface roughness, that is, an outer surface of which is roughly irregularly formed, such as a small spherical protrusion disposed on the outer surface, Respectively.

The ratio between the diameter d1 of the insulating core 11 and the thickness d2a and d2b of the shell 13 is in the range of 1: 1 to 20,000: 1, for example, in the range of 20: 1 to 6000: Can be selected. The diameter d1 of the insulating core 11 may be selected in the range of 1 占 퐉 to 100 占 퐉, for example, in the range of 3 占 퐉 to 10 占 퐉. The thicknesses d2a and d2b of the shell 13 may be selected from the range of 0.005 mu m to 1.0 mu m, for example, in the range of 0.01 mu m to 0.05 mu m.

When the ratio between the diameter d1 of the insulating core 11 and the thickness d2 of the shell 13 falls within the above-mentioned range, it can have both conductivity and durability.

The conductive particles 10 according to the embodiments of the present invention are configured such that the insulating core 11 and the shell 13 are in direct contact with each other and the entire outer surface of the insulating core 11 is tightly held by the shell 13 And the conductive particles 10 have no voids.

The shell 13 of the conductive particles 10 according to the embodiments of the present invention is formed to have a dense structure by a sputtering method. The conductive particles 10 having the shell 130 of a dense structure can improve the electrical conduction efficiency between the plurality of conductive particles 10. [

Hereinafter, a sputtering apparatus for the conductive particles 10 will be described first, followed by a sputtering method.

Of the conductive particles Sputtering  Device

FIG. 3 is a cross-sectional view schematically showing a sputtering apparatus for a conductive particle (hereinafter referred to as a sputtering apparatus) according to an embodiment of the present invention, FIG. 4 is a perspective view showing a separator disposed around the vessel in FIG. FIG. 5 is a side view of a portion of the separator of FIG. 4 taken partially. FIG.

3, a sputtering apparatus 1000 according to an embodiment of the present invention includes a chamber 100, a container 100 for holding the powder 1 of the insulating particles 11 of the conductive particles 10 provided in the chamber 100, (200), and a target (300).

The chamber 100 includes a gas exhaust port 105 for forming a vacuum state therein, and includes an introduction port 106 for introducing a gas used in the sputtering process, for example, an inert gas such as argon. The introduction port 106 may be disposed at a position adjacent to the target 300. For example, when the target 300 includes a plurality of first and second targets 310 and 320, the introduction port 106 may include a plurality of adjacent first and second targets 310 and 320, .

The container 200 is disposed in the lower portion of the chamber 100 and accommodates the powder 1 made of a plurality of insulating particles. Here, the insulating particles correspond to the insulating core 11 described above with reference to Figs. 2A to 2B. Hereinafter, they are referred to as insulating particles 11.

The container 200 may be fixedly disposed on the support 201. The support base 201 extends under the chamber 100 and includes a rotation axis 201c located on the same axis as the center of the vessel 200. [ In one embodiment, a motor 210 is provided outside the chamber 100 and the rotational force of the motor 210 is transmitted to the support 201 through the gears 221 and 223 and the belt 225. The container 200 can be rotated by the rotation of the support table 201.

The container 200 can be heated to a predetermined temperature by the heater 500. In one embodiment, the heater 500 is thermally coupled to the support 201 and heat generated in the heater 500 may be transferred to the vessel 200 through the support 201. In yet another embodiment, the heater 500 may be thermally connected directly to the vessel 200 to heat the vessel 200. The heater 500 may use infrared light, but the present invention is not limited thereto.

In this embodiment, the container 200 and the support 201 are described as separate members. However, in another embodiment of the present invention, the container 200 and the support 201 may be integrally formed.

The target 300 is disposed at an upper portion of the chamber 100 and faces the container 200. In one embodiment of the present invention, the target 300 may include a first target 310 and a second target 320 that are spaced apart from each other. The first and second targets 310 and 320 may include conductive materials, but may include the same or different materials. The first and second targets 310 and 320 may be formed of at least one selected from the group consisting of copper (Cu), nickel (Ni), chromium (Cr), silver (Ag), gold (Au), aluminum (Al), palladium (Pd) ), Tin (Sn), molybdenum (Mo), and alloys thereof.

The first target 310 and the second target 320 may be fixed to the first target holder 301 and the second target holder 302 to face the container 200, respectively. The first and second target holders 301 and 302 may be used as an electrode (cathode electrode) for plasma generation, respectively. Hereinafter, the first target holder 301 may be referred to as a first cathode electrode, and the second target holder 302 may be referred to as a second cathode electrode.

Referring to FIG. 4, a separator 400 is disposed within the vessel 200. The separator 400 mixes or stirs the powder 1 in the vessel 200 during the sputtering process so that the plurality of insulating particles 11 forming the powder 1 are uniformly exposed toward the target 300. [ The separator 400 may include first and second separators 410 and 420 that rotate relative to the vessel 200. In the present specification, "the A member rotates relative to the B member" means that the A member rotates with respect to the coordinate system moving with the B member.

The first separator 410 is disposed between the center of the vessel 200 and one end of the vessel 200. The first separator 410 includes a plurality of fins 411 arranged to be spaced apart from each other along the radial direction from the center of the container 200 to one end of the container 200. The first separator 410 may be connected to the chamber 100 by a support rod 413 extending upward. For example, the support rod 413 may extend toward the upper surface 101 (see FIG. 3) of the chamber 100 and be fixedly connected to the chamber 100.

The first separator 410 is disposed in the container 200 with respect to the central axis C of the container 200 in a state in which at least a part of the pins 411 are contained in the powder 1 The powder 1 is mixed or stirred while relatively rotating with respect to the powder 1. For example, when the first separator 410 is fixed to the upper portion 101 of the chamber 100 by the support rod 413 and a part of the plurality of fins 411 is contained in the powder 1, And can be rotated clockwise (or counterclockwise) by the rotation of the motor 210. The plurality of insulating particles 11 constituting the powder 1 in the container 200 are separated from the first separator 410 by a relative rotation of the first separator 410 with respect to the container 200, (411).

The second separator 420 may include a plate 421 extending obliquely to form an acute angle? With respect to the bottom surface 200b of the container 200 as shown in FIGS. The plate 421 is formed to have a larger area than the above-described fins 411, and may have a shape of irregularities such as a saw tooth shape.

 The plate 421 can rotate clockwise or counterclockwise around the rotation rod 423 connected to the plate 421. 3) disposed on the outer side of the chamber 100, and the rotation rod 423 is connected to the rotation shaft 423 and the rotation shaft 423. The rotation shaft 423 is connected to the motor 430 (see FIG. 3) disposed on the outer side of the chamber 100, The plate 421 can rotate around the rotation shaft 423 as a center axis. The rotation axis of the second separator 420, that is, the rotation rod 423 is disposed at a predetermined distance from the rotation axis C of the container 200.

Of the conductive particles Sputtering  fair

6 is a flowchart schematically showing a sputtering process of conductive particles according to an embodiment of the present invention.

3 and 6, the powder 1 of the insulating particles 11 is placed on the container 200 (S10). The insulating particles 11 may be made of an insulating resin. The insulating resin may be at least one resin selected from the group consisting of polymethyl methacrylate (PMMA), acrylic resin such as polymethyl acrylate, silicone resin such as polysiloxane, and polyolefin resin such as polyethylene, polypropylene and polystyrene . In yet another embodiment, the insulating resin is selected from the group consisting of polycarbonate, polysulfone, polybutylene, polyester, polyurethane, styrene butadiene, polyethersulfone, polyvinyl butyral, polyvinyl formal, polyvinylacetate, styrene divinyl benzene , An epoxy resin, and a phenol resin.

The insulating particles 11 are spherical particles having a diameter in the range of 1 탆 to 100 탆, for example, in the range of 3 탆 to 10 탆, and the state in which the plurality of insulating particles 11 are arranged in the container 200 Powder phase.

Then, the target 300 is placed in the chamber 100. The target 300 may include one or a plurality of first and second targets 310, 320 as shown in FIG.

Next, the inside of the chamber 100 is formed into a vacuum state having a predetermined pressure by using the exhaust port 105 in the chamber 100 (S11). The interior of the chamber 100 may have a vacuum degree of about 0.1 mTorr to 10 mTorr, but the present invention is not limited thereto.

Thereafter, an inert gas such as argon gas is supplied through the inlet 106 of the chamber 100, and a plasma is generated by applying power to the cathode electrode of the target 300 (S21). In one embodiment, the inert gas may be supplied at a flow rate between 10 sccm and 500 sccm, but the present invention is not limited thereto. As the power source applied to the cathode electrode, RF or DC power source can be used.

Ions or neutral particles of the plasma strike the surface of the target 300 and atoms separated from the target 300 are attached to each of the insulating particles 11 of the powder 1 to form a conductive coating. The conductive coating corresponds to the shell 13 described above with reference to Figs. 1 to 2B.

The sputtering method according to an embodiment of the present invention is for producing a plurality of conductive particles 10 (refer to Figs. 1 to 2B). A plurality of insulating particles 11 constituting a powder 1 in a container 200 Lt; / RTI > However, since the insulating particles 11 disposed under the plurality of insulating particles 11 in the container 200 are not covered with the insulating particles 11 and are not exposed toward the target 300, 300 may be difficult to adhere to the outer surface of the insulating particles 11. When the sputtering process continues in this state, the insulating particles 11 disposed on the lower part of the powder 1 are formed only on the outer surface of the insulating particles 11 disposed on the upper part of the powder 1, It is impossible to form a conductive film on the outer surface of the conductive film. Among the insulating particles 11 disposed on the top of the powder 1, a conductive coating is formed only on a portion of the outer surface exposed toward the target 300, and a conductive coating is not easily formed evenly on the insulating particles 11.

In order to prevent this, the embodiments of the present invention perform a process of mixing or stirring the powder 1 of a plurality of insulating particles 11 during the process of forming a conductive coating (S23). Through such a process, it is possible not only to form the conductive coating evenly on the plurality of insulating particles 11 forming the powder 1, but also to form the conductive coating on the outer surface of each of the insulating particles 11 uniformly can do.

The mixing or stirring process can use the separator 400 (see FIG. 4). 4, after the fins 411 of the first separator 410 are disposed so that at least a portion thereof is contained in the powder 1, the first separator 410 is placed in the container 200 So that the powder 1 can be mixed or stirred. For example, after the first separator 410 is arranged to extend along the radial direction from the center of the bottom surface 200b of the container 200 toward the edge of the container 200, the container 200 is rotated, It is possible to mix or stir the powders 1 in the powder mixer 200 uniformly.

4 and 5, after the plate 421 of the second separator 420 is disposed so that at least a portion thereof is contained in the powder 1, the second separator 420 is placed in the container 1, The powder 1 can be mixed or stirred by rotating relative to the powder 200. For example, the second separator 420 may be rotated by the motor 430 connected to the rotating rod 423 to evenly mix or stir the powder 1 in the container 200.

During rotation of the second separator 420, the container 200 may also rotate. The rotation axis of the second separator 420 and the rotation axis C of the vessel 200 may be spaced apart from each other by a predetermined distance and the number of rotations of the second separator 420 and the vessel 200 may be different from each other . For example, while the container 200 rotates once about the axis C, the second separator 420 rotates the rotating rod 423 about the center axis several to several tens of times so that the powder 1 in the container 200 ) Can be evenly mixed or stirred.

In the embodiment of the present invention, the process of mixing or stirring the powder 1 using any one of the first separator 410 and the second separator 420 has been described. However, in another embodiment, The powder 1 may be mixed or stirred using all of the powders 410 and 420.

Although not shown, the process of heating the container 200 to a predetermined temperature using the heater 500 during the steps S21 and S23 of forming the conductive film using the target 300 may be performed. The deposition (deposition) efficiency of the conductive particles on the outer surface of the insulating particles 11 can be improved through heating of the container 200.

Although not shown, before the step (S21, S23) of forming the conductive coating on the plurality of insulating particles 11 of the powder 1 by using the target 300, the outer surface of the insulating particles 11, May be performed. The insulating particles 11 are treated by plasma under a gas atmosphere in which oxygen and argon are mixed, so that the surface of the insulating particles 11 can be modified so that the conductive particles can easily adhere thereto. The bonding between the insulating particles 11 and the conductive film formed thereon can be further strengthened through the surface treatment process. The surface treatment process can be uniformly performed on the surface of the plurality of insulating particles 11 by using the first and second separators 410 and 420 as described above.

As an embodiment of the present invention, in the case of forming a single layer of conductive coating, i.e., shell 13, as shown in FIG. 2A, it is performed in accordance with the process described with reference to FIG. 6, A plurality of targets (e.g., first and second targets 310 and 320) may be installed and used in the chamber 100, or a plurality of targets (e.g., first and second targets 310 and 320)

When the first and second targets 310 and 320 of the same material are used, power supply to the first and second cathode electrodes 301 and 302 can be performed at the same time, and introduction of the inert gas can be performed in the first and second Can be accomplished simultaneously through the inlets 106 adjacent the targets 310 and 320, respectively.

As another embodiment of the present invention, when a multi-layer conductive film including different materials such as the first and second shells 13a and 13b is formed as shown in FIG. 2B, 1 and the second target 310, 320 may comprise different materials. Hereinafter, the sputtering process of the conductive particles having the multilayered first and second shells 13a and 13b will be described.

7 is a flowchart schematically showing a sputtering process of conductive particles according to another embodiment of the present invention.

Referring to FIGS. 3 and 7, the powder 1 is placed in the container 200 (S210). Then, the first and second targets 310 and 320 are installed. At this time, the first and second targets 310 and 320 include a conductive material, for example, a metallic material, but include different materials. The metallic material may be selected from the group consisting of copper (Cu), nickel (Ni), chromium (Cr), silver (Ag), gold (Au), aluminum (Al), palladium (Pd), titanium (Ti), tin Mo), and an alloy thereof.

Thereafter, the interior of the chamber 100 is evacuated (S211). As a non-limiting example of the present invention, the interior of the chamber 100 may have a degree of vacuum on the order of about 0.1 mTorr to 10 mTorr.

Thereafter, an inert gas such as argon gas is supplied through the inlet 106 of the chamber 100 and a power source (RF or DC power source) is applied to the first cathode electrode 301 of the first target 310 (S221). Ions or neutral particles of plasma generated around the first target 310 strike the surface of the first target 310 so that the first conductive atoms are separated from the first target 310 and the separated first conductive atoms are insulated And adheres to the outer surface of the particle 11 to form a first conductive film. The first conductive coating may correspond to the first shell 13a described with reference to FIG. 2B.

At this time, the step (S222) of mixing or stirring the powder 1 in the container 200 is performed to uniformly form the first conductive coating on the outer surface of each of the plurality of insulating particles 11. The mixing and stirring step S212 of the powder 1 may be performed using at least one of the first and second separators 410 and 420 as described with reference to FIGS. 3 to 6, As described above.

Plasma ions generated during the process of forming the first conductive coating using the first target 310 may be blocked from moving to the second target 320 by the shielding plate 350.

Thereafter, the power of the first cathode electrode 301 of the first target 310 is turned off (S223).

Next, a power source (RF or DC power source) is applied to the second cathode electrode 302 of the second target 320 (S231). The second target 320 includes a different material from the conductive material of the first target 310. Ions or neutral particles of plasma generated around the second target 320 strike the surface of the second target 320 to separate the second conductive atoms from the second target 320, 1 < / RTI > conductive film to form a second conductive film. The second conductive film may correspond to the second shell 13b described with reference to Fig. 2B.

At this time, the step (S232) of mixing or stirring the powder 1 in the vessel 200 is performed to uniformly form the second conductive coating on the first conductive coating of each of the plurality of insulating particles 11. The mixing and stirring step S212 of the powder 1 may be performed using at least one of the first and second separators 410 and 420 as described with reference to FIGS. 3 to 6, As described above.

Plasma ions generated during the process of forming the second conductive coating using the second target 320 may be blocked from moving to the first target 310 by the shielding plate 350.

Thereafter, the power of the second cathode electrode 302 of the second target 320 is turned off (S233).

As described above, since the steps of forming the first and second conductive coatings are successively performed under substantially the same pressure in the same chamber 100, other impurities such as, for example, The oxide layer is not interposed. In an embodiment of the present invention, when the first target 310 includes copper and the second target 320 includes an alloy of nickel and chromium, the sputtering process S211 to S213 using the first target 310 ), A second conductive film, which is an alloy film of nickel and chromium, is formed directly on the first conductive film as the copper film.

As described above, the conductive particles formed according to the embodiment of the present invention are distinguished from the conductive particles including the metal oxide layer between the multi-layered shells, because no metal oxide layer is interposed between the conductive coatings of the multi-layers.

As a comparative example of the present invention, when a process such as opening the chamber 100 and changing the target in the chamber 100 is added after the above-described sputtering process (S211 to S213), the first conductive film A thin film of copper oxide is formed. Thereafter, the shell having the completed multi-layer conductive film by performing the step of forming the second conductive film further includes an oxide layer such as copper oxide, and such an oxide layer can lower the electric conductivity of the conductive particle.

However, according to the embodiment of the present invention, by successively forming the first and second conductive coatings under substantially the same pressure in the same chamber 100, the oxide layer having a relatively low electrical conductivity is not interposed between the conductive coatings It is possible to form a multi-layered shell structure having a dense structure.

Although not shown, the process of forming the first conductive film (S211 to S213) using the first target 310 and the process of forming the second conductive film using the second target 320 (S221 to S223) A process of heating the container 200 to a predetermined temperature can be performed. The deposition efficiency of the first and second conductive atoms emitted from the first and second targets 310 and 320 can be improved through the heating of the container 200.

In the process described with reference to Figs. 6 and 7, the process of mixing or stirring the powder 1 in the container 200 by the separator 400 has been described, but the present invention is not limited thereto.

As another embodiment, a mixing or stirring process may use a vibrator (not shown) such as an actuator connected to the container 200. As the container 200 vibrates at a predetermined frequency, the powder 1 can be mixed. The vibrator may operate in lieu of or in conjunction with the separator 400.

The conductive film formed by the sputtering process according to the embodiments of the present invention, i.e., the shell 13, is clearly distinguished from the shell formed by a plating method (for example, electroless plating or electrolytic plating). Any shell formed by the plating method necessarily contains an organic matter derived from various dispersants, acidity regulators and the like, which are necessarily contained in the plating composition, and the conductivity is relatively lowered. Further, in any shell formed by the plating method, the film structure constituting the shell is relatively dense and there is a problem of occurrence of cracks. In addition, there is a problem that the conductivity is also deteriorated by cracks.

However, since the conductive film according to the embodiments of the present invention, i.e., the shell 13, does not include an organic substance as an impurity and has a dense film structure as compared with the plating method, the problem of crack generation and the problem of deterioration of conductivity can be solved .

In addition, since the sputtering process according to the embodiments of the present invention performs a process of mixing or stirring the powder 1 using a separator or a vibrator, the conductive particles 10 having the shell 13 having a uniform thickness are formed And the conductive particles 10 having the shell 13 having such a uniform thickness can be produced in large quantities. That is, the quality deviation between the plurality of conductive particles 10 can be minimized.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the exemplary embodiments, and that various changes and modifications may be made therein without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

1: Powder
10: conductive particles
11: core (insulating particle)
13: Shell (conductive film)
100: chamber
200: container
300: target
310: first target
320: second target
400: separator
410: first separator
411:
420: second separator
421: Plate
500: heater

Claims (14)

Providing a target including a conductive material so as to face a container containing a powder of a plurality of insulating particles;
Forming a conductive coating on each of the plurality of insulating particles by blowing the target in an inert gas atmosphere; And
And mixing or stirring the powder in the container,
Wherein the mixing or stirring step is a step of rotating at least part of the separator contained in the powder relative to the container,
Wherein the separator comprises a first separator and a second separator which rotate relative to the vessel,
Wherein the first separator comprises a plurality of fins disposed between the center of the container and one end of the container and arranged to be spaced apart from each other along a radial direction from the center of the container to one end of the container, And the plate is connected to a rotating rod connected to the rotating motor connected to the outside of the chamber and rotates about the rotating rod as the rotating rod rotates By weight based on the total weight of the conductive particles. The method according to claim 1,
In the mixing or stirring step,
Wherein the step of forming the conductive film is performed during the step of forming the conductive film. delete delete The method according to claim 1,
In the mixing or stirring step,
And vibrating the vessel. ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1,
Wherein the step of forming the conductive film comprises:
Forming a first conductive coating on each of the plurality of insulating particles using a first target containing a first conductive material; And
And forming a second conductive coating on the first conductive coating using a second target comprising a second conductive material different from the first conductive material. The method according to claim 6,
Wherein the step of forming the first conductive coating film and the step of forming the second conductive coating film,
In the same chamber, and continuously under substantially the same pressure. The method according to claim 6,
Wherein the first conductive material comprises copper,
Wherein the second conductive material comprises at least one of nickel, chromium, and alloys thereof. The method according to claim 1,
Wherein the step of forming the conductive film comprises:
A method of sputtering conductive particles using a target comprising a metallic material to form a single layer of conductive coating. 10. The method of claim 9,
Wherein the metallic material comprises silver. The method according to claim 1,
Further comprising the step of applying heat to the container. The method according to claim 1,
Wherein the insulating particles comprise a resin. 13. The method of claim 12,
Wherein the resin is an acrylic resin. 13. A conductive particle produced according to any one of claims 1, 2 and 5 to 13.

Images