JP2014127467A - Conductive particle and conductive material containing conductive particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive particle with a projection and an anisotropic conductive material having low connection resistance, little variation of conductive performance of the particle and excellent in electrical conduction reliability.SOLUTION: There is provided a conductive particle containing a resin fine particle and a coating layer arranged on an outside surface of the resin fine particle and having a projection on its surface, and manufactured complying with a deformation volume (μm) when force with which destruction of the conductive particle is started (F2, mN) is added and the deformation volume (μm) when force with same value as a diameter of the conductive particle (F1, mN) is added. There is also provided an anisotropic conductive material containing such conductive particle.

Description

  The present invention relates to conductive particles and conductive materials including conductive particles, and more particularly to conductive particles with protrusions and conductive materials including conductive particles used in a fine pitch circuit.

  The conductive particles are used by being mixed and dispersed with a curing agent, an adhesive, a resin binder, and the like. An anisotropic conductive material such as an anisotropic conductive film, an anisotropic conductive paste is used. (Anisotropic Conductive Paste), anisotropic conductive ink (Anisotropic Conductive Ink), anisotropic conductive sheet (Anisotropic Conductive Sheet) and the like are widely used.

  For example, an anisotropic conductive material may be a TFT (Thin) on a substrate when assembling a flat panel display panel such as an LCD (Liquid Crystal Display), an AMOLED (Active Matrix Organic Emitting Diode), or a PDP (Plasma Display Panel). And an electrical connection with a driver IC (Integrated Circuit) for driving the TFT.

  In general, conductive particles used as such an anisotropic conductive material include metal particles such as nickel, copper, silver, and gold, carbon particles such as carbon powder, carbon fiber, and carbon flakes, and resin particles. Examples thereof include composite particles used by coating or plating a metal substance.

  Metal-based particles are conductive and have a wide particle size distribution. Therefore, PDPs that require a large circuit pitch and a high current are required rather than fields that require fine circuit pitch and high precision. Is mainly used for.

  Since carbon-based particles have a lower electrical conductivity than metal-based particles, their use is limited in fields where high electrical conductivity is required.

  On the other hand, composite particles are the most commonly used conductive particles because the electrical conductivity is about the middle between the metal particles and the carbon particles and the distribution of fine particles can be made very narrow. is there.

  Composite conductive particles can be used as they are by forming an alloy plating layer such as nickel-phosphorus, nickel-boron, nickel-phosphorus-tungsten or nickel-boron-tungsten on a spherical resin by electroless plating. A precious metal such as gold or silver is used in the outermost shell for the purpose of prevention and improvement of electrical conductivity.

  Since the composite conductive particles use a resin having a spherical flat surface, the surface is almost smooth. For example, an oxide film such as a 3-9 nm oxide film formed on the surface of an aluminum wiring pattern. Exists. Therefore, such an oxide film cannot be broken, and the resin used for the anisotropic conductive material cannot be effectively punched out, so that there is a problem that contact resistance increases or reliability decreases. there were.

  As a method for solving such a problem, a method of projecting protrusions on conductive particles has been devised (see, for example, Patent Documents 1 to 6 below).

JP 2006-228474 A JP 2006-216388 A JP 2006-228475 A JP 2006-302716 A JP 2006-344416 A JP 2007-35573 A

  However, in the case of the conductive particles with protrusions described above, the resin that is the core of the conductive particles cannot withstand the compressive force in the process of compressing and bonding to the circuit board, resulting in excessive deformation, which effectively oxidizes the protrusions. There was another problem that a phenomenon in which the film could not be broken and a phenomenon in which the resistance was not sufficiently reduced occurred.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to provide a projection having a low connection resistance, a small variation in the conductive performance of particles, and excellent conductivity reliability. An object of the present invention is to provide conductive particles and an anisotropic conductive material using the conductive particles.

  In order to solve the above-described problem, according to one aspect of the present invention, a resin particle and a coating layer provided on the outer surface of the resin particle and having a protrusion on the surface, the P value according to the following formula 1 is 20 Conductive particles are provided, wherein ≦ P ≦ 50.

P (μm ⁻¹ ) = [(Sf / Sc) / D] × 100 (Formula 1)

Here, in Equation 1 above,
Sf: Denaturation amount (μm) when a force (F2, mN) at which the conductive particles start to break is applied
Sc: Deformation amount (μm) when force (F1, mN) having the same numerical value as the diameter of the conductive particles is applied
D: Average diameter of conductive particles (μm)
Indicates.

  The coating layer preferably has a thickness of 30 to 300 nm.

  The protrusions preferably have a height of 50 nm to 500 nm.

  The protrusion is preferably made of the same material as the coating layer.

  The coating layer is preferably made of one or more alloys selected from the group consisting of Ni, Sn, Ag, Cu, Pd, Zn, W, P, B, and Au.

  Preferably, the outer surface of the coating layer further includes an additional coating layer made of one or more alloys selected from the group consisting of Au, Pt, Ag, and Pd.

  The conductive particles may be included in an anisotropic conductive film (ACF) for COG (Chip on Glass).

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, the anisotropic electrically-conductive material containing said electrically-conductive particle is provided.

  In order to solve the above problems, according to still another aspect of the present invention, an electronic device including the above conductive particles or the above anisotropic conductive material is provided.

  In the conductive particles according to the present invention, the ratio of compression deformation to fracture deformation is adjusted when an external force is applied, so that the circuit does not malfunction due to poor connection or rapid increase in resistance.

  In addition, the anisotropic conductive material according to the present invention has excellent electrical resistance and conductive reliability by using conductive particles having low electrical resistance and excellent conductive reliability.

It is a graph which shows the compression deformation state by the force of the electrically-conductive particle which concerns on the Example of this invention. It is explanatory drawing for demonstrating the deformation amount in the Example of this invention. It is a schematic diagram for demonstrating the action mechanism based on the Example of this invention. It is a schematic diagram for demonstrating the action mechanism based on the Example of this invention. It is a schematic diagram for demonstrating the action mechanism based on the Example of this invention. It is a schematic diagram for demonstrating the action mechanism based on the Example of this invention. It is a schematic diagram for demonstrating the action mechanism based on the Example of this invention. It is a schematic diagram for demonstrating the action mechanism based on the Example of this invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  Before describing the present invention more specifically, the terminology used herein is for the purpose of describing particular embodiments and examples only, and is defined by the scope of the present invention as defined by the claims. It should be understood that this is not a limitation. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise specified.

  Throughout this specification and claims, unless otherwise noted, the term “comprising” is meant to include the stated article, step or group of things, and step, and any other thing. It is not intended to exclude a stage or a group of things or a group of stages.

  On the other hand, the various embodiments and examples of the present invention may be combined with any other embodiments and examples unless clearly indicated to the contrary. In particular, any feature that indicates suitability or advantage may be combined with any other feature that indicates suitability or advantage.

  The conductive particles according to one embodiment of the present invention include resin fine particles and a coating layer provided on the outer surface of the resin fine particles.

  The resin fine particles are made of a known monomer polymer. Such materials include, but are not limited to, for example, polymerization using monomers such as styrene-based, acrylic-based, divinylbenzene-based or the like, or modified monomers thereof, or monomers mixed with the monomers. It is preferable to use a polymer obtained in this manner.

  As such resin fine particles, for example, those having an average particle diameter of 1.70 to 7.5 μm are preferably used.

  The coating layer may be formed of a metal. Such metals include, for example, gold (Au), silver (Ag), nickel (Ni), copper (Cu), tin (Sn), zinc (Zn), titanium (Ti), lead (Pb), tungsten (W). Or a single metal such as tin-lead, tin-copper, tin-zinc, nickel-phosphorus, nickel-boron, or nickel-tungsten.

  The thickness of the coating layer is preferably about 30 nm to 300 nm, for example. When the thickness of the coating layer is less than 30 nm, the resistance value increases. When the thickness of the coating layer exceeds 300 nm, peeling of the coating layer occurs, so that the reliability of the product is lowered. A particularly preferable thickness of the coating layer is 80 nm to 200 nm.

  Projections are provided on the surface of the covering layer. The height of the protrusion is not particularly limited, but is preferably 50 nm to 500 nm. This is because if the height of the protrusion is out of the above range, the effect of breaking the metal oxide layer and the binder resin is weakened. On the other hand, the height of the more preferable protrusion is 100 nm to 300 nm.

  The shape of the protrusion is not particularly limited, but is preferably a convex shape. In particular, when the protrusion is used as an anisotropic conductive material, it is preferable that the protrusion has a hardness that can break the resin binder and the metal oxide layer in the pressure bonding process.

  The material capable of giving such hardness is mainly metal, for example, gold (Au), silver (Ag), copper (Cu), nickel (Ni), titanium (Ti), bismuth (Bi). ), Antimony (Sb) or the like, or an alloy such as copper-zinc, copper-tin, nickel-phosphorus, nickel-tungsten, nickel-boron, or the like. Particularly preferred metals for forming the protrusions are nickel, gold, silver, palladium, tungsten and the like.

  An additional coating layer containing a noble metal such as gold, silver, platinum (Pt), palladium (Pd) may be further provided on the surface layer of the conductive particles. This is because the conductivity of the conductive particles can be increased and an antioxidant effect can be obtained.

  The formation method of said layer is not specifically limited, A general well-known technique, for example, sputtering, plating, vapor deposition etc., can be used.

  The conductive particles according to the embodiment of the present invention including the resin fine particles as described above and the coating layer having protrusions are deformed at an early stage due to an increase in pressure when pressure is applied. When the pressure exceeds a certain level, the conductive particles are destroyed. At this time, even if breakdown occurs, electricity can be transmitted through the conductive coating layer because of the property of electricity flowing along the surface.

  At this time, the conductive particles according to the present invention reflecting the above-described characteristics satisfy that the P value according to the following formula 1 is 20 ≦ P ≦ 50. When P is less than 20, the conductive particles are likely to be denatured during compression bonding, a part or most of the compression force is used as deformation energy, and the projection has a sufficient force to penetrate the oxide layer. There is a problem in that the resistance is not sufficiently reduced because it is not received. If P exceeds 50, the jig (Jig) is removed during compression bonding, and the recovery rate of the conductive particles occurs when the anisotropy resin is not yet cured. There is a problem that a short circuit between the electrode and the conductive particles occurs and the resistance increases.

P (μm ⁻¹ ) = [(Sf / Sc) / D] × 100 (Formula 1)

Here, in Equation 1 above,
Sf: Denaturation amount (μm) when a force (F2) at which the destruction of the conductive particles starts is applied
Sc: deformation amount (μm) when a force (F1) having the same numerical value as the diameter of the conductive particles is applied,
D: Average diameter of conductive particles (μm)
Indicates.

  Data necessary for calculating the P value can be obtained by using a micro compression tester (MCT). This will be described with reference to FIG. 1 and FIG.

  FIG. 1 is a graph showing the amount of deformation when a force is increased to a maximum of 100 mN by increasing the force at a speed of 0.33 mN / sec by a micro compression tester. FIG. 2 shows the amount of deformation of FIG. It is explanatory drawing for demonstrating. In this case, the deformation amount (S) refers to the amount by which the height of the conductive particles is reduced in the direction in which the force is applied when the force (F) is applied.

  From this, when the compression / destruction test is performed on the conductive particles with a force of 100 mN, the amount of compressive deformation (Sc) corresponding to the force (F1) having the same numerical value as the diameter of the conductive particles can be obtained. The fracture deformation amount (Sf) corresponding to the starting force (F2) can be obtained.

  For example, when the average diameter (D) of the conductive particles is 5 μm, a compression / destructive test is performed with a load of 100 mN at the maximum. At this time, the average diameter (D, μm) of the conductive particles is used as 5, The deformation amount (Sc) corresponding to 5 mN which is the same force (F1, mN) can be obtained. At this time, the use of the force (F1) numerically corresponding to the average diameter (D) is an element derived usefully empirically in order to reflect the amount of deformation due to size.

  In addition, the amount of deformation rapidly increases with the same force on the graph, and the force (F2) when the conductive particles start to break can be obtained, and the amount of breakage deformation (Sf) corresponding to the force can be obtained.

  On the other hand, the size of the conductive particles including the length of the protrusions is not limited, but the conductive particles are preferably manufactured to have an average diameter of 2 μm to 8 μm, for example. When the size of the conductive particles is less than 2 μm, the surface roughness of the electrode and the size of the conductive particles are similar, so the effect of the P value and resistance do not match. Further, when the size of the conductive particles exceeds 10 μm, it is meaningless because the conductive particles are not substantially used.

  The above-mentioned average diameter of the conductive particles is a mode value measured using, for example, a particle size analyzer (BECKMAN MULTISIZER TM3). At this time, it is preferable that the number of measured conductive particles (Particle Size Analyzer) (BECKMAN MULTISIZER TM3) is 150,000.

  Below, the mechanism according to the stage which the electrically-conductive particle which concerns on this invention acts is demonstrated, referring FIGS. Each drawing shows a state in which the ACF is located between the first electrode and the second electrode. For example, the conductive particles are conductive particles included in an ACF for COG (Chip on Glass), The electrode is located on the FPCB (flexible printed circuit board), and the second electrode is located on the glass substrate.

  FIG. 3 is a pre-joining step for joining the electrodes between the electrodes, and this step is intended for convenience of operation and accurate positioning of the electrodes. At this time, no force is applied between the first electrode and the second electrode, and a slight touch is made. The conductive particles and the electrode are not yet in contact.

  FIG. 4 is a stage in which a force starts to be applied between the electrodes, and a state where the conductive particles between the first electrode and the second electrode come into contact with each electrode by applying a force to the first electrode. . Application of force between the electrodes is performed via a jig (Jig) or the like.

  FIG. 5 is a stage in which a force is further applied between the electrodes. When a force is further applied to the first electrode, deformation of the conductive particles occurs, and the protrusion penetrates through the oxide film of the electrode. At this time, since the conductive particles have a small deformation rate although they are not torn, the protrusions can easily penetrate the oxide film and enter. When deformation increases or destruction progresses at this time, Sc has an important meaning because it cannot receive the force of the protruding particles penetrating the electrode.

  FIG. 6 is a stage where a strong force is applied between the electrodes and the conductive particles exceed the range of fracture or plastic deformation, and the conductive particles are deformed by 60% or more. However, even if the conductive particles are torn, electric transmission is possible along the conductive coating layer on the surface.

  FIG. 7 is a stage where the force applied between the electrodes is removed, and the resin for anisotropic conductive film is cured. Since the ACF resin is not yet completely cured, the conductive particles described above do not break down. Therefore, if the recovery rate of the conductive particles is large, there is no force to push and maintain the electrodes. The distance between them increases, causing a short circuit or increased resistance. However, in the present embodiment, since the conductive particles are destroyed and no recovery is performed, the possibility of a short circuit or resistance becomes very low. Therefore, Sf has an important meaning.

  FIG. 8 shows a state where the ACF resin is completely cured and is safely bonded.

  Hereinafter, the conductive particles and the anisotropic conductive material according to the embodiment of the present invention will be described in detail with reference to Examples and Comparative Examples. In addition, the Example shown below is an example of the electrically-conductive particle and anisotropic conductive material which concern on embodiment of this invention, Comprising: The electrically-conductive particle and anisotropic conductive material which concern on embodiment of this invention are the following. It is not limited to the embodiment shown.

[Example 1]
15 g of dispersion stabilizer “PVP-30K” 15 g was dissolved in 1600 g of deionized water. To this solution, 85 g of hexanediol diacrylate monomer and 85 g of divinylbenzene monomer were added, and a suspension was prepared while stirring. To this suspension, 1.5 g of benzoyl peroxide as a polymerization agent was added and mixed well by stirring. The suspension was heated at 85 ° C. to conduct a polymerization reaction, and maintained for 12 hours until the reaction was completed. After the synthesis was completed, the fine particles in the suspension were filtered, washed, classified, and dried to obtain core resin fine particles.

On the other hand, when electroless plating is performed so that the resin particles have protrusions, activated nuclei to which the reduced metal particles adhere at the time of plating are necessary. For example, resin core particles etched with an alkali solution or an acid solution are sensitized with a solution of hydrochloric acid (HCl) and tin chloride (SnCl ₂ ) dissolved in deionized water, and deionized. Acceleration is performed with a solution of hydrochloric acid and palladium chloride (PdCl ₂ ) in water. The sensitizing is a step of adsorbing Sn ²⁺ ions on the surface of the insulating material, and the acceleration is for forming a catalyst nucleus for electroless plating by a reaction represented by Sn ²⁺ + Pd ²⁺ → Sn ⁴⁺ + Pd ⁰ . It is a catalyst treatment process.

  Next, 2200 mL of deionized water was charged into a 3 L reactor, 240 g of nickel sulfate as a Ni salt, 5 g of sodium acetate as a complexing agent, 0.002 g of Pb-acetate as a stabilizer, and surface activity 3 g of PEG-400 as an agent was sequentially dissolved in deionized water to prepare a plating solution (a). 30 g of fine particles having an average diameter of 2.79 μm, which had been subjected to the Pd catalyst treatment step described above, were placed in the plating solution (a) and subjected to a dispersion treatment for 5 minutes using a homogenizer. After the dispersion treatment, the pH was adjusted to 6.5 using aqueous ammonia.

  300 mL of deionized water, 260 g of sodium hypophosphite as a reducing agent, and 0.001 g of Pb-acetate as a stabilizer were sequentially dissolved in a 1 L beaker to obtain a solution (b).

The temperature of the 3 L reactor was maintained at 65 ° C., and the solution (b) was added at a rate of 20 mL / min for 5 minutes with a metering pump while stirring at 250 rpm, and the rest was charged at 8 mL / min. (B) When all of the solutions were added, the reaction was maintained for 20 minutes to obtain an average diameter of 3.01 μm, Sc 1.45 μm, Sf 2.56 μm, P 39.4 μm ⁻¹ , plating layer thickness 110 nm, and protrusions Conductive particles having a height of 125 nm were produced.

  At this time, a mode value measured using a Particle Size Analyzer (BECKMAN MULTISIZER TM3) was used as the average diameter of the conductive particles. The number of conductive particles measured was 150,000.

  Further, the thickness of the plating layer is halved by using the above-mentioned Particle Size Analyzer (BECKMAN MULTISIZER TM3) to halve the difference between the size mode value of the fine particles before plating and the size mode value of the conductive particles after plating. It was measured. At this time, the number of particles measured was 150,000.

  In addition, the height of the protrusion was measured by using a scanning electron microscope (FESEM, Field Emission Scanning Electron Microscope), and the height of the protrusion was measured from the spherical virtual horizon of the conductive particles, and indicated as an average value.

In addition, the deformation rate was measured using a micro compression tester (FISHERSCOPE) using a plane indenter (Indenter) having a side length of 50 μm.
HM2000). The deformation rate was determined by measuring five conductive particles and averaging them. Specifically, the hot plate is heated at 25 ° C., the conductive particles are placed thereon, the indenter descending speed is set to 0.33 mN / sec, and the measurement is performed with a maximum force of 100 mN, thereby deforming the conductive particles. The deformation rate (S) was measured.

[Example 2]
Fine particles having an average diameter of 3.15 μm were synthesized in the same manner as in Example 1 except that 85 g of trimethylolpropane triacrylate monomer and 85 g of divinylbenzene monomer were used. After passing through the same pre-plating treatment process as in Example 1 using 20 g of the fine particles, the solution (b) was initially charged at a rate of 20 mL / min for 5 minutes, and then the rest was charged at 6 mL / min. Conductive particles having an average diameter of 3.47 μm, Sc of 1.04 μm, Sf of 1.72 μm, P of 47.7 μm ⁻¹ , a plating layer thickness of 160 nm and a protrusion height of 230 nm were produced.

[Example 3]
Fine particles having an average diameter of 3.85 μm were synthesized in the same manner as in Example 1 except that 85 g of ethylene glycol dimethacrylate monomer and 85 g of divinylbenzene were used. A plating process similar to that in Example 1 was performed using 50 g of the fine particles, and the average diameter was 4.02 μm, Sc 1.48 μm, Sf 1.78 μm, P 29.79 μm ⁻¹ , the thickness of the plating layer was 85 nm, and the height of the protrusions A conductive particle having a thickness of 151 nm was produced.

[Example 4]
Fine particles having an average diameter of 4.9 μm were synthesized in the same manner as in Example 1 except that 51 g of ethylene glycol dimethacrylate monomer and 119 g of divinylbenzene were used. After passing through the same plating pretreatment step as in Example 1 using 75 g of the fine particles, the solution (b) was charged at a rate of 20 mL / min for the initial 5 minutes, and then the rest was charged at 15 mL / min. Conductive particles having an average diameter of 5.05 μm, Sc of 1.67 μm, Sf of 2.56 μm, P of 30.4 μm ⁻¹ , a plating layer thickness of 78 nm and a protrusion height of 65 nm were produced.

[Example 5]
Fine particles having an average diameter of 7.6 μm were synthesized in the same manner as in Example 1 except that 85 g of ethylene glycol dimethacrylate monomer and 85 g of methyl methacrylate were used. A plating process similar to that of Example 2 was performed using 50 g of the fine particles, and the average diameter was 7.96 μm, Sc 1.85 μm, Sf 3.95 μm, P 26.8 μm ⁻¹ , plating layer thickness 180 nm, and protrusion height Conductive particles having a thickness of 246 nm were produced.

[Example 6]
After 15 g of the fine particles synthesized in Example 3, the same pretreatment process as in Example 1 was performed, and then the solution (b) was charged at a rate of 20 mL / min for the initial 5 minutes, and then the rest was 5 mL / min. The conductive particles having an average diameter of 4.4 μm, Sc 1.35 μm, Sf 1.87 μm, P 31.5 μm ⁻¹ , plating layer thickness 275 nm and protrusion height 425 nm were produced.

[Example 7]
80 g of fine particles synthesized in Example 3 were used for the same pretreatment step as in Example 1, and then solution (b) was charged at an initial rate of 20 mL / min for 5 minutes. Thereafter, the remainder is charged at a rate of 15 mL / min to form a Ni-P plating layer, and Au plating using a substitution reaction is performed to obtain an average diameter of 3.96 μm, Sc 1.35 μm, Sf 1. Conductive particles having a thickness of 74 μm, P 31.8 μm ⁻¹ , a plating layer thickness of 55 nm, and a protrusion height of 52 nm were produced.

[Example 8]
Ni-P plating was performed in the same manner as in Example 1 using 40 g of the fine particles synthesized in Example 3, and the plated conductive particles were subjected to Cu plating. An MS-KAPA product manufactured by MSC was used for Cu plating. As a result, conductive particles having an average diameter of 4.11 μm, Sc 1.52 μm, Sf 1.76 μm, P 28.2 μm ⁻¹ , a plating layer thickness of 130 nm, and a protrusion height of 133 nm were produced.

[Comparative Example 1]
Fine particles having an average diameter of 2.83 μm were synthesized in the same manner as in Example 1 except that 170 g of styrene monomer was used. The same plating step as in Example 1 was performed using 30 g of the fine particles, and the average diameter was 3.04 μm, Sc 1.98 μm, Sf 1.12 μm, P 18.6 μm ⁻¹ , plating layer thickness 105 nm, and protrusion height Conductive particles having a thickness of 135 nm were produced.

[Comparative Example 2]
It carried out similarly to the process of the comparative example 1, and gave final Cu plating. Thus, conductive particles having an average diameter of 3.08 μm, Sc 1.98 μm, Sf 1.12 μm, P 18.6 μm ⁻¹ , a plating layer thickness of 125 nm, and a protrusion height of 124 nm were manufactured.

(Experimental example)
<Experimental example 1: measurement of connection resistance>
In order to measure the connection resistance, the epoxy resin and the conductive particles were mixed, formed into a film, joined to the electrode, and then the resistance was measured.

  The initial resistance and the change in resistance after 100 hours at 85 ° C./85% were measured, and the results are shown in Table 1 below.

  As is apparent from Table 1 above, it can be seen that the resistance of the P range of 20 ≦ P ≦ 50 according to the embodiment of the present invention is low and the connection reliability is high.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

Claims (9)

Resin fine particles,
A coating layer provided on the outer surface of the resin fine particles and having protrusions on the surface;
Including
The electroconductive particle whose P value by following formula 1 is 20 <= P <= 50.

P (μm ⁻¹ ) = [(Sf / Sc) / D] × 100 (Formula 1)

Here, in Equation 1 above,
Sf: Denaturation amount (μm) when a force (F2, mN) at which the conductive particles start to break is applied
Sc: Deformation amount (μm) when force (F1, mN) having the same numerical value as the diameter of the conductive particles is applied
D: Average diameter of conductive particles (μm)
Indicates.   The conductive particle according to claim 1, wherein the coating layer has a thickness of 30 to 300 nm.   The conductive particle according to claim 1, wherein the protrusion has a height of 50 nm to 500 nm.   The conductive particle according to claim 1, wherein the protrusion is made of the same material as the coating layer.   The said coating layer consists of 1 type, or 2 or more types of alloys selected from the group which consists of Ni, Sn, Ag, Cu, Pd, Zn, W, P, B, and Au. 2. Conductive particles according to item 1.   The outer surface of the said coating layer further contains the additional coating layer which consists of 1 type, or 2 or more types of alloys selected from the group which consists of Au, Pt, Ag, and Pd. Conductive particles according to 1.   The conductive particles according to claim 1, wherein the conductive particles are included in an anisotropic conductive film (ACF) for COG (Chip on Glass).   An anisotropic conductive material comprising the conductive particles according to claim 1.   An electronic device comprising the conductive particles according to claim 1 or the anisotropic conductive material according to claim 8.

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