KR20080051117A - Plastic conductor - Google Patents

Abstract

A plastic conductive material is provided to realize significantly improved binding force between a plastic bead and an intermediate metal plating layer as well as between an intermediate metal plating layer and a solder layer, thereby improving mechanical and electrical properties of an electric appliance using the same. A plastic conductive material comprises: a plastic bead; one to three intermediate metal plating layers formed on the plastic bead; and an outermost solder layer formed on the intermediate metal plating layers, wherein each of the plastic bead and intermediate metal plating layers has surface irregularities. The surface irregularity formed on the plastic bead has at least one form selected from dimple forms and embossed forms having repeated peaks and valleys.

Description

Plastic Conductor

The present invention relates to a plastic conductive material for a package, and more specifically, irregularities are formed on the surfaces of each of the plastic beads and the intermediate metal plating layer so that the bonding force between the plastic beads and the intermediate metal plating layer or between the intermediate metal plating layer and the outermost solder layer is improved. It relates to a plastic conductive material that can greatly improve the mechanical and electrical properties of the package when the final product is mounted.

Metal solder balls, which are conventional conductive materials for packages, were manufactured using an atomizing method or a uniform size, and then melted and cooled, or a piezoelectric material. Various alloy systems have been used mainly on elements such as silver (Ag), copper (Cu), and zinc (Zn) with lead (Pb) as the main axis.

In addition, as the amount of light and small portable devices and the amount of production of light and small portable devices have increased in recent years, there is a growing demand for high reliability characteristics, which are more difficult than ever in the related packaging industry. In particular, the existing metal solder ball is a product of the thermal shock test, which is an essential item for electronic component evaluation, due to the difference of the coefficient of thermal expansion (CTE) between the upper package and the lower PCB and the growth of inter-metallic compound (IMC) at the bonding interface. It is known to adversely affect the reliability, and due to the characteristics of portable devices to which BGA and CSP packaging are widely applied, the reliability of impact and deformation is highly demanded. The situation is looking for a solution.

Recently, several kinds of metal layers are formed on a spherical plastic having a similar CTE (Coefficient of Thermal Expansion) value to a PCB substrate, and research for developing a product having dynamic and thermal reliability superior to that of a conventional metal solder ball is being conducted. That is, the plastic conductive material is designed so that the primary plastic material acts as a buffer against dynamic and thermal stress, unlike the conventional metal conductive material, and the inner plastic including the intermediate metal layer can maintain a constant height during packaging. As a result, the reliability of the entire package is known to be improved.

In addition, in the case of a metal conductive material, it is difficult to precisely control the shape of the electronic package when small diameters are used, and since a general resistance heating dissolution method is used, it is difficult to precisely control the composition between the products, thereby increasing the distribution of physical properties. On the other hand, the plastic conductive material is easy to cope with small diameters, and has an advantage of enabling uniform shape and size, and uniform composition and physical properties due to the electrical and chemical metal layer formation method.

However, in the case of the plastic conductive material, since the heterogeneous bonding between the plastic and the metal is made, high adhesion between the two dissimilar layers is required. However, the metal layer formation method through the pre-treatment and metal reduction of the general plastic surface has a bad adhesion between the heterogeneous and adversely affect the reliability of the final product.

The present invention has a structure in which one to three intermediate metal plating layers and one outermost solder layer are sequentially formed on the plastic beads, in order to solve the problems of the conventional plastic conductive material as described above, the plastic beads and the intermediate metal plating layer Provided is a plastic conductive material having irregularities formed on each surface thereof.

In addition, the present invention is the irregularities are formed on the surface of each of the plastic bead and the intermediate metal plating layer to significantly improve the bonding force between the plastic bead and the intermediate metal plating layer or between the intermediate metal plating layer and the outermost solder layer to mechanically package the final product In addition, it provides a plastic conductive material that can improve the electrical properties.

In the plastic conductive material of the present invention for achieving the above object, in the plastic conductive material consisting of a plastic bead, one to three intermediate metal plating layers formed on the plastic beads and the outermost solder layer formed on the intermediate metal plating layer, Concave-convex is formed on the surface of each of the plastic bead and the intermediate metal plating layer.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Unevenness is formed on the surface of the plastic beads as shown in FIG. 2.

The unevenness formed on the surface of the plastic bead is one kind selected from the form of ripples and embossed forms in which protrusions and recesses are repeated.

FIG. 1 is a scanning electron microscope (SEM) photograph of plastic beads in which unevenness is formed on the surface by chemical treatment, and FIG. 2 is a scanning electron microscope (SEM) photograph of plastic beads in which irregularities are formed on the surface by chemical treatment.

One example of a method of forming irregularities on the surface of the plastic beads may be prepared by treating the plastic beads with an etchant to etch the surface of the plastic beads.

The etchant is composed of 50 ~ 300g / L chromic acid and 10 ~ 100g / L potassium permanganate, the etching process is preferably performed for 1 to 2 hours at 60 ~ 90 ℃.

The plastic beads are preferably provided with a compressive elasticity of 400 ~ 500kgf / mm2.

On the other hand, irregularities are formed on the surface of the intermediate metal plating layer as shown in FIG.

The unevenness formed on the surface of the intermediate metal plating layer is one type selected from the form of embossing and the embossing form in which the protrusion and the indentation are repeated.

FIG. 3 is a scanning electron microscope (SEM) photograph of an intermediate metal plating layer in which unevenness is formed on a surface by an artificial treatment, and FIG. 4 is a scanning electron microscope (SEM) photograph of an intermediate metal plating layer in which an unevenness is formed on a surface by an artificial treatment. to be.

One example of a method of forming an uneven surface on the surface of the intermediate metal plating layer is a temperature at the end of the plating process when forming a new intermediate metal plating layer by electroplating or electroless plating a metal plating solution on the plastic beads or the intermediate metal plating layer. The method of increasing the precipitation rate to 70 ~ 90 ℃ is used.

The heavy metal plating layer is composed of a metal or an alloy having a melting point of 300 ° C. or more, and the outermost solder layer is composed of a metal or an alloy having a melting point of less than 300 ° C.

Specifically, the intermediate metal plating layer is made of copper (Cu) or nickel (Ni), and the outermost solder layer is made of an alloy including tin (Sn) or tin (Sn).

Specific examples of the alloy containing tin (Sn) include Sn / Pb alloys, Sn / Ag alloys, Sn / Ag / Cu alloys, Sn / Cu alloys, Sn / Zn alloys, Sn / Bi alloys, and the like.

The thickness of the outermost solder layer is 0.1 to 5.0% of the total radius of the plastic conductive material, and the total outer diameter of the plastic conductive material is preferably 1 to 1,000 µm.

The present invention is a two-layer structure consisting of a first intermediate metal plating layer formed on the plastic beads and the second intermediate metal plating layer formed on the first intermediate metal plating layer, the first metal plating layer is composed of Ni The second metal plating layer includes a plastic conductive material made of Cu.

The thickness of the first intermediate metal plating layer is 0.1 to 1.0% of the total radius of the plastic conductive material, the thickness of the second intermediate metal plating layer is preferably 0.1 to 2.5% of the total radius of the plastic conductive material.

In addition, irregularities may be formed only on the surface of the first intermediate metal plating layer among the first intermediate metal plating layer and the second intermediate metal plating layer, and irregularities may not be formed on the surface of the second intermediate metal plating layer.

5 is a runner electron microscope (SEM) photograph of a second intermediate metal plating layer of the present invention in which irregularities are formed on the surface by artificial treatment, and FIG. 6 is a runner electron microscope (SEM) showing a surface state of a plastic conductive material according to the present invention. 7 is a photograph of a runner electron microscope (SEM) showing a cross-sectional state of a plastic conductive material according to the present invention.

The plastic conductive material according to the present invention may be manufactured through the following steps.

1) etching through the surface of the plastic beads by etching to form a dimple (dimple),

2) forming a first intermediate metal plating layer on the bead surface with a thickness of 0.1 to 10% of the radius of the entire plastic conductive material,

3) forming an artificial coining and embossing type irregularities on the surface of the first intermediate metal plating layer;

4) forming a second intermediate metal plating layer on the surface of the first intermediate metal plating layer on which the unevenness is formed,

5) optionally forming irregularities in the form of artificial coining and embossing on the surface of the second intermediate metal plating layer,

6) forming the outermost solder layer to a thickness of 0.1 to 50% of the total radius of the plastic conductive material.

An example of a method of manufacturing the plastic conductive material of the present invention will be described in more detail.

plastic Bead  Produce

Plastic beads of the present invention may be prepared by any one method selected from the group consisting of suspension polymerization method, emulsion polymerization method, dispersion polymerization method and seed polymerization method, preferably prepared by suspension polymerization method.

More specifically, the plastic beads of the present invention are polystyrene-based, polyethylene-based, polypropylene-based, styrene-acrylonitrile copolymer (SAN) -based, low-density polyethylene (LDPE) -based, high-density prepared by suspension polymerization or seed polymerization. Any one selected from the group consisting of polyethylene (HDPE), acrylonitrile butadiene copolymer (ABS), and expandable polystyrene (EPS) is used.

At this time, the plastic beads are spherical particles having a particle size of 0.1 ~ 1,000um.

plastic Bead  Surface unevenness and pretreatment

After the plastic beads are manufactured, the plastic beads may be subjected to a surface treatment process and / or a pretreatment process before the intermediate metal plating layer is formed in order to improve adhesion between the plastic beads and the intermediate metal plating layer.

Specifically, the plastic beads are impregnated with a degreasing solution containing 50 g / L of a degreasing agent in 15 g / L of NaOH, and degreased at 60 ° C. for 10 minutes and washed three times;

In order to impart unevenness to the degreased plastic beads, the surface treatment was performed by impregnating an etching solution containing 50 to 300 g / L of chromic acid and 10 to 100 g / L of potassium permanganate for 1 to 2 hours at 60 to 90 ° C. Doing;

10 to 40 g of the etched plastic beads were impregnated into a mixed solution composed of 2 to 6 g of SnCl ₂ , 15 ml of hydrochloric acid, 200 ml of water, and 1 ml of Triton X-100, stirred at room temperature for about 1 hour, and then washed with water three times. To prepare Sn-adsorbed plastic beads; And

The Sn-adsorbed plastic beads were impregnated into a mixed solution composed of 0.02 to 0.05 g of PdCl ₂ , 1 ml of hydrochloric acid, 500 ml of water, and 1 ml of Triton X-100, and then reacted at 60 to 90 ° C. for 1 hour, and washed with water once. After stirring for 10 minutes using 15% sulfuric acid by volume, and washed three times with water, to prepare a Pd-adsorbed plastic beads; may be carried out.

Specifically, the surface etching step was carried out by etching the plastic beads in an etching solution composed of 150 g / L chromic anhydride, 50 g / L KMnO ₄ , 350 ml of water and 100 ml of sulfuric acid, followed by stirring and etching at 60 to 90 ° C. for 1 hour. Wash with 4 times, wash with 1% by volume of 10% sulfuric acid, and wash again with water once.

Sn and Pd are adsorbed by treating the bead surface with a pretreatment solution containing SnCl ₂ in a composition consisting of hydrochloric acid, water and a surfactant as described above and a pretreatment solution containing PdCl ₂ in the composition. At this time, by adding the surfactant to the pretreatment solution, the plating structure can form a metal plating layer of dense and uniform thickness, it is possible to produce a shiny plastic beads (surface) formed.

First intermediate Metal plating layer

Electroless plating using a metal plating solution on the surface of the plastic bead to form a first intermediate metal plating layer, wherein the first intermediate metal plating layer of the present invention is preferably a nickel plating layer.

Specifically, in order to electroless nickel-plated plastic beads having surface roughness treatment and pretreatment, 2.5 to 20 g of nickel sulfate, 2.5 to 20 g of sodium acetate, 1.2 to 0 g of maleic acid, and 2.5 to 20 g of sodium phosphite as reducing agents Impregnated in a nickel plating solution composed of 0.5 to 4 ml of sodium acetate, 100 ppm lead acetate, and 1 to 8 ml of Triton X-100, and electroless plating at 50 to 70 ° C., and the thickness of the plating layer was 0.1 Changes can be made in the range of ~ 10%. After washing three times with water to form a nickel plating layer (first intermediate metal plating layer).

First intermediate Metal plating layer  Surface roughness step

After completing the electroless plating process of forming the first intermediate metal plating layer as the first step, the process may be further performed in the same process, and by increasing the deposition rate at the end of the plating process to 70-90 ° C., 1 Unevenness is formed on the surface of the intermediate metal plating layer.

2nd middle Metal plating layer  Forming steps

In addition, a step of forming a second intermediate metal plating layer by electroless or electroplating using a dissimilar metal plating solution on the primary metal plated plastic beads, wherein the second intermediate metal plating layer is preferably a copper plating layer. will be.

The second intermediate metal plating layer is made of nickel-plated plastic beads with 3.0 to 15 g of copper sulfate, 3.5 to 17 g of EDTA, 0.2 to 200 mg of 2,2-bipyridine as a stabilizer, 0.1 to 500 mg of surfactant PEG-1000, and 37% formaldehyde as a reducing agent. Impregnated in a copper plating solution with a pH of 9.5-13.5 consisting of 2.0-10 ml, electroless plating at 10-60 ° C, or nickel-plated plastic beads 10-100 g of clarifier, 10-150 g of blue soda, caustic 5 Prepare a plating solution composed of ~ 80g, 10-110g of Rochelle's salt, working temperature 10 ~ 100 ℃, concentration 15 ~ 18B / e, PH 12.2 ~ 12.6, cathode current density 0.1 ~ 2.5A / dm ² , cathode to anode area ratio It can be electroplated in the range of 1: 1.5 ~ 1: 5, 2 ~ 8RPM of barrel rotation speed, and the thickness of plating layer can be changed in the range of 0.1 ~ 25% of the radius of the entire plastic conductive material, and then washed three times with water. The second intermediate metal plating layer may be formed.

2nd middle Metal plating layer  Surface roughness step

The electroless or electroplating process of forming the second intermediate metal plating layer may be further completed in the same process after the first step, and the deposition rate may be increased by raising the temperature to 60 to 90 ° C. at the end of the plating process. As a result, irregularities are formed on the surface of the second intermediate metal plating layer.

Outermost Solder layer  Forming steps

The outermost solder layer formed thereafter is formed of a metal having a melting point of 300 ° C. or less, preferably a Sn-based alloy, more preferably in a Sn / Ag-based, Sn / Cu-based, Sn / Ni-based, or Sn / Bi-based metal. It is formed of one or more selected alloys, the thickness of the plating layer can be changed in the range of 0.5 to 50% of the radius of the entire plastic conductive material.

The Sn-based alloy plating layer (solder layer) may be formed by bathing in a plating solution selected from the group consisting of Sn / Ag based, Sn / Cu based, Sn / Ni based, and Sn / Bi based, followed by electroplating.

At this time, the outer diameter of the plastic beads after the process to obtain a beads of less than 1,000 um has a problem of floating on the plating liquid because the density is low, there is a problem that can not be performed by the conventional electroplating method occurs, to compensate for this The mesh barrel electroplating method with improved electroplating is used.

That is, in order to solve the problem of floating on the plating liquid, 0.1 mm to 3.0 cm of media balls are mixed with the plastic core beads at a ratio of 1/2 to 1/20, so that the inner surface of the anode dangler and barrel for improvement of electroplating The plated body is dispersed and electroplated by widening the current distribution.

More specifically, the electroplating is performed by deforming the method of driving the mesh barrel to 6 to 10 rpm in the conventional 360 degree rotation to 1 to 5 rpm in both directions of 200 degrees to the left and right. In addition, in the structure of a conventional hexagonal barrel, one surface is opened in an open type to introduce a plating solution, so that the plating solution is circulated smoothly. At this time, the electroplating was performed at a plating current of 0.2 to 0.8 μm / min at a cathode current density of 0.1 to 10 A / dm ² , a plating solution temperature of 10 to 30 ° C., a barrel rotation speed of 1 to 8 rpm, and a cathode current density of 1 A / dm ² . do.

In the present invention, irregularities are formed on each surface of the plastic bead and the intermediate metal plating layer, thereby greatly improving the bonding force between the plastic bead and the intermediate metal plating layer or the bonding force between the intermediate metal plating layer and the outermost solder layer to thereby mechanically and electrically package the final product. Physical properties can be improved.

As a result, the plastic conductive material of the present invention is useful for applications such as packaging of semiconductor devices, packaging of FDD, and the like.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited to these examples.

Example  One

On the surface of plastic beads having an average diameter of 310 μm prepared by homopolymerization of divinyl benzene, an etching solution composed of 150 g / L chromic acid, 50 g / L potassium permanganate, 350 ml of water, and 100 ml of sulfuric acid was impregnated for 1 hour at 70 ° C. After surface etching and surface treatment, a nickel plating layer having a thickness of 4 μm is first formed, and then the plating temperature is raised to 80 ° C. to form artificial irregularities with a deviation of 0.5 μm. A copper plating layer having a thickness of μm was formed, and finally, an electroplating solder layer having a thickness of 50 μm of Sn / Ag alloy of 96.5 wt% of Sn and 3.5 wt% of Ag was formed to prepare a plastic conductive material having a diameter of 450 μm.

Example  2

On the surface of plastic beads having an average diameter of 310 μm prepared by homopolymerization of divinyl benzene, an etching solution composed of 150 g / L chromic acid and 50 g / L potassium permanganate, 350 ml of water, and 100 ml of sulfuric acid was impregnated for 1 hour at 70 ° C. After surface etching and surface treatment, firstly, a nickel plating layer having a thickness of 4 μm is formed, and then the plating temperature is raised to 80 ° C. to form artificial irregularities of 0.5 μm deviation, and secondly to the surface of the nickel beads thus formed. Form a 16um thick copper plating layer, and at the last step of copper plating, work temperature is raised to 80 ℃ to form artificial irregularities of 1.5um deviation, and then Sn / Ag alloy of 96.5% by weight and 3.5% by weight of Sn / Ag alloy is 50㎛ thick. Electroplating was performed to prepare a plastic conductive material having a diameter of 450 μm.

Comparative Example  One

4um thick nickel plating layer was formed on the surface of the average 310um diameter plastic beads prepared by homopolymerization of divinyl benzene, and a 16um thick copper plating layer was formed on the nickel bead surface. The Sn / Ag alloy was electroplated to a thickness of 50 μm to prepare a plastic conductive material having a diameter of 450 μm.

Comparative Example  2

In general, the Ag / Cu / Sn alloy composed of 3.0% by weight of Ag, 0.5% by weight of Cu, and 96.5% by weight of Sn is dissolved in an inert melting furnace manufactured by SUS using a known method of preparing a metal conductive material, and the composition is stirred to have a uniform composition. Inert chamber designed to separate droplets and have a temperature gradient from the melting point of the solder alloy to room temperature by vibrating a piezoelectric device installed directly above the nozzle while quantitatively pressurizing nitrogen from the top through a micro nozzle processed at the bottom. The metal conductive material having an average diameter of 450 mu m was prepared by freezing the mixture with free fall.

Comparative Example  3

In general, a Ag / Sn alloy composed of 3.5% by weight of Ag and 96.5% by weight of Sn is dissolved in an inert melting furnace made of SUS using a known method of manufacturing a metal conductive material, and stirred to have a uniform composition, and a fine nozzle processed at the bottom thereof. By virtue of quantitatively pressurizing nitrogen from the top through a vibration using a piezo device installed directly above the nozzle, the droplets are separated and free-falled and cooled in an inert chamber designed to have a temperature gradient from the melting point of the solder alloy to room temperature. A metal conductive material having a diameter of 450 μm was prepared.

Comparative Example  4

In general, the Ag / Cu / Sn alloy composed of 1.0% by weight of Ag, 0.5% by weight of Cu, and 98.5% by weight of Sn is dissolved in an inert melting furnace made of SUS using a known method of preparing a metal conductive material, and the composition is stirred to have a uniform composition. Inert chamber designed to separate droplets and have a temperature gradient from the melting point of the solder alloy to room temperature by vibrating a piezoelectric device installed directly above the nozzle while quantitatively pressurizing nitrogen from the top through a micro nozzle processed at the bottom. The metal conductive material having an average diameter of 450 mu m was prepared by freezing the mixture with free fall.

Experimental Example 1 Measurement of Shear Strength Average and Standard Deviation After Cross-Section

For the products of Examples 1 to 2 and Comparative Examples 1 to 4, the shear strength was measured 20 times using a shearing strength measuring apparatus (Bonding shear & pull tester, Dage series 4000, Dage Holdings Ltd., UK) , And the standard deviation accordingly is shown in Table 1.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Average shear strength (gF) 887 923 753 776 714 698 Standard Deviation 39.2 40.5 44.3 58.2 54.9 51.9

As shown in Table 1, as shown in the results of Examples 1 and 2 it can be seen that the average of the shear strength is improved compared to the conventional plastic conductive material of Comparative Example 1, the standard deviation is about the same but slightly It can be seen that there is a tendency to decrease.

<Experiment 2> Drop impact experiment based on electrical characteristics after double-sided mounting

For the products of Examples 1 to 2 and Comparative Examples 1 to 4, each of 12 drop impact tests of the JEDEC standard was carried out, and the average of the results of measuring the number of breaks was determined based on the time point at which the electrical short circuit occurred. It is shown in Table 2.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Average number of breaks 59 73 43 14 29 36

As shown in Table 2, as shown in the results of Examples 1 and 2 and Comparative Example 1, it can be seen that showing the average value of the physical properties superior to the metal conductive material of the same size of a variety of plastic conductive material, surface uneven treatment It can be seen that one case is superior in physical properties than the other.

<Experiment 3> Bending impact experiment based on electrical characteristics after double-sided mounting

For each of the products of Examples 1 to 2 and Comparative Examples 1 to 4, the bending impact tests of the JEDEC standard were performed 12 times each, and the average of the results of measuring the number of breaks based on the time point at which the electrical short circuit occurred. It is shown in Table 3.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Average number of breaks 12,736 16,104 9,012 2,795 6,881 7,245

As shown in Table 3, as shown in the results of Examples 1 and 2 and Comparative Example 1, it can be seen that the average value of the physical properties superior to the metal conductive material of various same size of the plastic conductive material, surface uneven treatment It can be seen that one case is superior in physical properties than the other.

Experimental Example 4 Thermal Shock Experiment Based on Electrical Characteristics After Double-sided Mounting

For the products of Examples 1 to 2 and Comparative Examples 1 to 4, 12 samples of thermal shock experiments (test conditions: -65 ° C to + 150 ° C and 30 min / 1 zone) of JEDEC standards were performed. Table 4 shows the average of the results of measuring the number of cycles at break based on the point of electrical short circuit.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Average number of break cycles 1,518 1,581 1,334 1,224 1,175 1,156

As shown in Table 4, as shown in the results of Examples 1 and 2 and Comparative Example 1, it can be seen that showing the average value of the physical properties superior to the metal conductive material of the same size of a variety of plastic conductive material, surface uneven treatment It can be seen that one case is superior in physical properties than the other.

1 is a scanning electron microscope (SEM) photograph of a plastic bead in which unevenness is not formed on a surface by a chemical treatment.

2 is a scanning electron microscope (SEM) photograph of plastic beads having irregularities formed on the surface by chemical treatment,

3 is a scanning electron microscope (SEM) photograph of the first intermediate metal plated layer of the present invention in which no irregularities are formed on the surface by artificial treatment.

4 is a scanning electron microscope (SEM) photograph of the first intermediate metal plating layer of the present invention in which irregularities are formed on the surface by artificial transition,

5 is a runner electron microscope (SEM) photograph of the second intermediate metal plating layer of the present invention in which irregularities are formed on the surface by artificial treatment,

Figure 6 is a runner electron microscope (SEM) photograph showing the surface state of the plastic conductive material according to the present invention,

Figure 7 is a runner electron microscope (SEM) photograph showing a cross-sectional state of the plastic conductive material according to the present invention.

Claims (13)

In a plastic conductive material consisting of a plastic bead, one to three intermediate metal plating layers formed on the plastic beads, and an outermost solder layer formed on the intermediate metal plating layer, irregularities are formed on surfaces of each of the plastic beads and the intermediate metal plating layer. A plastic conductive material, characterized in that formed. The plastic conductive material of claim 1, wherein the irregularities formed on the surface of the plastic bead are one selected from a ripple form and an embossed form in which protrusions and recesses are repeated. The method of claim 1, wherein the irregularities formed on the surface of the intermediate metal plating layer is a plastic conductive material, characterized in that one selected from the embossed form of the embossing (coining) form and the protrusion and the indentation is repeated. The plastic conductive material according to claim 1, wherein the intermediate metal plating layer is one selected from a metal and an alloy having a melting point of 300 ° C or higher. The plastic conductive material according to claim 1, wherein the outermost solder layer is one selected from a metal or an alloy having a melting point of less than 300 ° C. The plastic conductive material according to claim 1, wherein the plastic beads have a compressive elasticity of 400 to 500 kgf / mm 2. The plastic conductive material according to claim 1, wherein the outermost solder layer is one selected from an alloy containing Sn and Sn. The thickness of the outermost solder layer is a plastic conductive material, characterized in that 0.1 to 5.0% of the total radius of the plastic conductive material. The plastic conductive material according to claim 1, wherein the total outer diameter of the plastic conductive material is 1 to 1,000 µm. The method of claim 1, wherein the intermediate metal plating layer is a two-layer structure consisting of a first intermediate metal plating layer formed on the plastic beads and a second intermediate metal plating layer formed on the first intermediate metal plating layer, the first metal plating layer is Ni And the second metal plating layer is made of Cu. The plastic conductive material according to claim 10, wherein the thickness of the first intermediate metal plating layer is 0.1 to 10% of the total radius of the plastic conductive material. The plastic conductive material according to claim 10, wherein the thickness of the second intermediate metal plating layer is 0.1 to 25% of the total radius of the plastic conductive material. The plastic conductive material according to claim 10, wherein there are irregularities only on the surface of the first intermediate metal plating layer among the first intermediate metal plating layer and the second intermediate metal plating layer.

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