KR20150052363A - Conductive particles, conductive material and connection structure - Google Patents

Abstract

Provided are conductive particles capable of suppressing aggregation of a plurality of conductive particles and capable of lowering the connection resistance between electrodes when used for connection between electrodes and a conductive material using the conductive particles. A conductive particle 1 according to the present invention comprises a base particle 2 and a conductive layer 3 disposed on the surface of the base particle 2 and containing at least one metal component selected from nickel, boron, tungsten and molybdenum Layer (3). The conductive material according to the present invention includes conductive particles (1) and a binder resin.

Description

TECHNICAL FIELD [0001] The present invention relates to conductive particles, conductive materials, and connection structures,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive particle having a conductive layer disposed on a surface of a base particle, and more particularly, to conductive particles usable for electrical connection between electrodes, for example. The present invention also relates to a conductive material and a connection structure using the conductive particles.

Anisotropic conductive paste such as anisotropic conductive paste and anisotropic conductive film are widely known. In these anisotropic conductive materials, conductive particles are dispersed in the binder resin.

The anisotropic conductive material is used for connection between the IC chip and the flexible printed circuit board and for connection between the IC chip and the circuit board having the ITO electrode. For example, after the anisotropic conductive material is disposed between the electrodes of the IC chip and the electrodes of the circuit board, these electrodes can be electrically connected by heating and pressing.

As an example of the above conductive particles, Patent Document 1 below discloses a conductive particle in which a nickel conductive layer or a nickel alloy conductive layer is formed on the surface of spherical base particles having an average particle diameter of 1 to 20 탆 by electroless plating, . The conductive particles have minute protrusions of 0.05 to 4 占 퐉 in the outermost layer of the conductive layer. The conductive layer and the protrusions are connected substantially continuously.

In the following Patent Document 2, there is disclosed a conductive particle having base particles and a conductive layer formed on the surface of the base particles. A divinylbenzene-ethylvinylbenzene mixture is used as a part of the monomer to form the base particles. In this conductive particle, the compressive modulus when the particle diameter is displaced by 10% is 2.5 x 10 ⁹ N / m 2 or less, the compressive strain recovery rate is 30% or more, and the fracture strain is 30% or more. Patent Document 2 discloses that when the electrodes of the substrate are electrically connected using the conductive particles, the connection resistance is lowered and the connection reliability is increased.

Japanese Patent Application Laid-Open No. 2000-243132 Japanese Patent Application Laid-Open No. 2003-313304

When the electrodes are connected using the conductive particles described in Patent Document 1, the connection resistance between the electrodes may be increased. When an anisotropic conductive material including the conductive particles described in Patent Document 1 is used to connect the electrodes, the resin component between the electrode and the conductive particles may not be sufficiently removed. Therefore, the connection resistance between the electrodes connected by the conductive particles contained in the anisotropic conductive material may be increased.

In the conductive particles of the embodiment of Patent Document 1, a conductive layer containing nickel and phosphorus is formed. There are many cases where an oxide film is formed on the surface of the conductive layer of the electrode and the conductive particles which are connected by the conductive particles. When the electrodes are connected using the conductive particles having a conductive layer containing nickel and phosphorus, since the conductive layer containing nickel and phosphorus is relatively soft, it is impossible to sufficiently remove the oxide film on the surfaces of the electrodes and conductive particles The connection resistance may be increased.

In addition, in order to lower the connection resistance, if the thickness of the conductive layer including nickel and phosphorus as described in Patent Document 1 is increased, the member to be connected or the substrate may be damaged by the conductive particles. If the member to be connected or the electrode is damaged, the connection resistance tends to be high. In addition, if the electrode or the member to be connected is damaged, the reliability of conduction between the electrodes becomes low.

Further, in the conventional conductive particles as described in Patent Document 1, a plurality of conductive particles sometimes aggregate. When a plurality of cohesive conductive particles are used to connect the electrodes, a short circuit may occur between the electrodes.

In addition, even in the case of the conductive particles described in Patent Document 2, the oxide film can not be sufficiently removed or damage to the member to be connected or the substrate can not be suppressed. For this reason, even when the conductive particles described in Patent Document 2 are used, it is difficult to sufficiently lower the connection resistance between the electrodes.

It is an object of the present invention to provide an electroconductive particle capable of suppressing aggregation of a plurality of electroconductive particles and capable of lowering the connection resistance between electrodes when used for connection between electrodes and a conductive material and a connection structure using the electroconductive particles .

SUMMARY OF THE INVENTION It is a particular object of the present invention to provide a conductive particle which can effectively eliminate an electrode and an oxide film on the surface of a conductive particle when used for connection between electrodes, To provide a connection structure.

SUMMARY OF THE INVENTION It is a particular object of the present invention to provide a conductive material and a connection structure capable of effectively eliminating the resin component between the electrode and the conductive particle when used for connection between the electrodes, thereby lowering the connection resistance between the electrodes.

According to a broad aspect of the present invention, there is provided a conductive particle having base particles and a conductive layer disposed on a surface of the base particles and having a conductive layer containing at least one metal component selected from nickel, boron, tungsten, and molybdenum do.

In a specific aspect of the conductive particles according to the present invention, the content of boron in the entire 100 wt% of the conductive layer is 0.05 wt% or more and 4 wt% or less.

In a specific aspect of the conductive particles according to the present invention, the content of the metal component in the entire 100 wt% of the conductive layer is 0.1 wt% or more and 30 wt% or less.

In a specific aspect of the conductive particles according to the present invention, the content of the metal component in the entire 100 wt% of the conductive layer is more than 5 wt% and 30 wt% or less.

In certain aspects of the conductive particles according to the present invention, the metal component comprises tungsten.

In a specific aspect of the conductive particles according to the present invention, the compression modulus when the conductive particles are compression-deformed by 10% is not less than 5000 N / mm 2 and not more than 15000 N / mm 2.

In some specific aspects of the conductive particles according to the present invention, the compression recovery rate is not less than 5% and not more than 70%.

In certain aspects of the conductive particles according to the present invention, the metal component comprises molybdenum.

In a specific aspect of the conductive particles according to the present invention, the conductive layer includes nickel and molybdenum, and the content of nickel in the entire 100 wt% of the conductive layer is 70 wt% or more and 99.9 wt% or less, The content is 0.1% by weight or more and 30% by weight or less.

In a specific aspect of the conductive particle according to the present invention, the conductive particles have a compressive modulus at 5% compression of 7000 N / mm < 2 > or more and a compressive strength of more than 10% A crack is generated in the conductive layer.

In a specific aspect of the conductive particles according to the present invention, the thickness of the conductive layer is 0.05 占 퐉 or more and 0.5 占 퐉 or less.

In a specific aspect of the conductive particles according to the present invention, the conductive layer has projections on the outer surface.

The conductive material according to the present invention includes the above-described conductive particles and a binder resin.

The connecting structure according to the present invention includes a first connecting object member, a second connecting object member, and a connecting portion connecting the first and second connecting object members, wherein the connecting portion is formed by the above- Or formed of a conductive material containing the conductive particles and a binder resin.

In the conductive particle according to the present invention, since the conductive layer containing at least one metal component of nickel, boron, tungsten and molybdenum is arranged on the surface of the base particle, . In addition, when the electrodes are connected using the conductive particles according to the present invention, the connection resistance can be lowered.

1 is a cross-sectional view showing a conductive particle according to a first embodiment of the present invention.
2 is a cross-sectional view showing conductive particles according to a second embodiment of the present invention.
3 is a cross-sectional view showing a conductive particle according to a third embodiment of the present invention.
4 is a front sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention.
5 is a schematic cross-sectional view for explaining a state when the conductive particles are compressed.
6 is a schematic view showing an example of a relationship between a compression load value and a compression displacement when a conductive layer is cracked when the conductive particles are compressed.

Hereinafter, the details of the present invention will be described.

The conductive particles according to the present invention have base particles and a conductive layer disposed on the surface of the base particles and containing at least one metal component selected from the group consisting of nickel, boron, tungsten and molybdenum. The conductive layer is a nickel-boron-tungsten / molybdenum conductive layer. Hereinafter, at least one kind of metal component among tungsten and molybdenum may be described as the metal component M. Hereinafter, the conductive layer containing nickel, boron, and the metal component M may be described as the conductive layer X.

By employing the above-described configuration of the conductive particles according to the present invention, aggregation of the plurality of conductive particles can be suppressed. The aggregation of the plurality of conductive particles can be suppressed. As a result, short-circuiting between the electrodes can be effectively prevented. Further, by employing the above-described configuration of the conductive particles according to the present invention, the connection resistance can be lowered when the electrodes are connected using the conductive particles according to the present invention.

When the electrodes are connected by the conductive particles having a conductive layer containing nickel, the connection resistance between the electrodes is lowered. If the content of nickel in the total 100 wt% of the conductive layer X in the conductive particles according to the present invention is 50 wt% or more, the connection resistance between the electrodes is considerably low. Therefore, it is preferable that the content of nickel in the entire 100 wt% of the conductive layer X is 50 wt% or more.

Further, in the conductive particles having a nickel conductive layer not containing boron, since the nickel conductive layer containing no boron is excessively soft, it is not possible to sufficiently remove the oxide film on the surfaces of the electrodes and the conductive particles at the time of connection between the electrodes, The connection resistance may be increased. For example, in the case of the conductive particles having a conductive layer containing nickel and phosphorus, the electrode and the oxide film on the surface of the conductive particles can not be fully removed, and the connection resistance tends to increase. Particularly, if the content of phosphorus in the entire 100 wt% of the conductive layer is 10.5 wt% or more, the connection resistance tends to be high, and if it is 1 wt% or more, the connection resistance tends to become higher.

On the other hand, if the thickness of the conductive layer including nickel and phosphorus is made thick in order to lower the connection resistance, the member to be connected or the substrate may be damaged by the conductive particles.

On the other hand, since the hardness of the conductive layer X including nickel and boron is relatively high, the connection resistance between the electrodes can be reduced. It is possible to exclude the electrode and the oxide film on the surface of the conductive particle at the time of connection between the electrodes, thereby making it possible to lower the connection resistance.

Further, in the conductive particles according to the present invention, since the conductive layer X includes not only boron but also at least one kind of metal component M of tungsten and molybdenum, the conductive layer X containing boron and the metal component M is formed into a relatively short . Therefore, the electrode and the oxide film on the surfaces of the conductive particles can be sufficiently removed, and the connection resistance can be reduced considerably. Particularly, when the conductive layer X includes the metal component M and the conductive layer X has protrusions on the outer surface, the oxide film on the electrode and the surface of the conductive particles can be more effectively excluded and the connection resistance can be further reduced can do.

Further, since the conductive layer X includes the metal component M, the conductive layer X becomes quite hard. As a result, even if an impact is applied to the connection structure in which the electrodes are connected by the conductive particles, conduction failure is less likely to occur. That is, the impact resistance of the connection structure can be increased.

In addition, since the surface magnetism of the conductive layer of the conventional conductive particles is high and the surface magnetism of the conductive layer containing nickel and boron is high, when the electrodes are electrically connected to each other, Due to the influence of the particles, the electrodes adjacent to each other in the transverse direction tend to be easily connected. In the conductive particle according to the present invention, since the conductive layer X includes the metal component M, the surface magnetism of the conductive layer X is considerably lowered. Therefore, aggregation of a plurality of conductive particles can be suppressed. Therefore, when the electrodes are electrically connected to each other, it is possible to suppress the connection between the electrodes adjacent to each other in the transverse direction by the agglomerated conductive particles. That is, it is possible to further prevent a short circuit between adjacent electrodes.

It is preferable that the content of nickel is not less than 70 wt% and not more than 99.9 wt%, and the content of the metal component M is not less than 0.1 wt% and not more than 30 wt% in 100 wt% of the entire conductive layer X. Further, it is preferable that the conductive layer X does not contain phosphorus, or that the conductive layer X contains phosphorus, and the content of phosphorus in the entire 100 wt% of the conductive layer X is less than 1 wt%.

Wherein the content of nickel is at least 70 wt% and not more than 99.9 wt%, the content of the metal component M is at least 0.1 wt% and at most 30 wt%, and the conductive layer X is phosphorus Or the content of phosphorus in the entire 100 wt% of the conductive layer X is less than 1 wt%, while the conductive layer X contains phosphorus. When the conductive particles having this preferable constitution are used for connection between the electrodes, it is possible to effectively exclude the electrodes and the oxide film on the surfaces of the conductive particles. Therefore, the connection resistance between the electrodes in the resulting connection structure can be further reduced. Further, since the content of nickel in the conductive particles having this preferable constitution is 70% by weight or more, the connection resistance between the electrodes is considerably low.

In addition, since the content of the metal component M in the entire 100 wt% of the conductive layer X is 0.1 wt% or more and 30 wt% or less, the conductive layer X is considerably larger than the conductive layer containing no metal component M It becomes hard. As a result, the electrode and the oxide film on the surface of the conductive particle can be effectively removed, resulting in further lowering of the connection resistance between the electrodes. In addition, when the conductive particles and the binder resin are blended and the electrodes are connected to each other by using a conductive material, the connection resistance between the electrodes is further reduced even by effectively eliminating the resin component between the electrodes and the conductive particles.

The compression modulus (10% K value) when the conductive particles according to the present invention are compressed and deformed by 10% is preferably 5000N / mm2 or more, more preferably 7000N / mm2 or more, preferably 15000N / Lt; 2 > / mm < 2 > or less. When the above-mentioned compressive elasticity modulus (10% K value) is equal to or lower than the lower limit, the oxide film on the surface of the electrode and the conductive particles can be excluded more effectively and the resin component between the electrode and the conductive particles can be excluded more effectively. The connection resistance between the electrodes is further reduced.

The compression modulus (10% K value) can be measured in the following manner.

The conductive particles are compressed using a micro compression tester under the conditions of a smooth indenter end face of a circumference (diameter 50 탆, made of diamond), a compression rate of 2.6 mN / sec, and a maximum test load of 10 gf. The load value N and the compression displacement (mm) at this time are measured. From the obtained measured values, the above-mentioned compressive modulus can be obtained by the following formula. As the micro-compression tester, for example, "Fisher Scope H-100" manufactured by Fisher Company is used.

K value (N / mm 2) = (3/2 ^1/2 ) · F · S ^-3/2 · R ^-1/2

F: load value (N) when the conductive particles are 10% compressively deformed

S: Compressive displacement (mm) at 10% compressive deformation of conductive particles

R: radius of conductive particle (mm)

The compression recovery rate of the conductive particles is preferably 5% or more, more preferably 20% or more, preferably 70% or less, more preferably 60% or less, further preferably 50% or less. When the compression recovery rate is not less than the lower limit and not more than the upper limit, the oxide film on the surface of the electrode and the conductive particle can be more effectively excluded and the resin component between the electrode and the conductive particle can be excluded more effectively. The connection resistance is further lowered. Further, it is more difficult to cause peeling at the interface between the portion of the cured product and the connecting portion excluding the conductive particles, and the conductive particles and the member to be connected. Further, as a result of suppressing the repulsive force of the conductive particles used for connection between the electrodes, the conductive material becomes difficult to peel off from the substrate or the like. Even in this respect, the connection resistance between the electrodes is further reduced.

The compression recovery rate can be measured as follows.

The conductive particles are dispersed on the sample stand. (Reversed load value) is applied to the dispersed conductive particles until the conductive particles are compressively deformed by 30% in the center direction of the conductive particles using a micro compression tester. Thereafter, the load is removed to the original point load value (0.40 mN). And the compression-recovery rate can be obtained from the following equation by measuring the load-compression displacement between them. The load speed is 0.33 mN / sec. As the micro-compression tester, for example, "Fisher Scope H-100" manufactured by Fisher Company is used.

Compression recovery rate (%) = [(L1-L2) / L1] 100

L1: Compressive displacement from the original point load value to the reverse load value when the load is applied

L2: No-load displacement from the inverse load value when the load is released to the original point load value

The compressive modulus of elasticity and the compression recovery rate are determined by the kind of the base particles, the particle diameter of the base particles, the content of nickel in the entire 100 wt% of the conductive layer X, M, the content of phosphorus in the entire 100 wt% of the conductive layer X, the content of boron in the total 100 wt% of the conductive layer X, the thickness of the conductive layer X, and the like.

In the conductive particles according to the present invention, it is preferable that the compression modulus (5% K value) when compressed at 5% is 7000 N / mm < 2 >

In the conductive particle according to the present invention, it is preferable that cracks occur in the conductive layer when the conductive particles are compressed to more than 10% and not more than 25% of the particle diameter of the conductive particles before compression in the compression direction. In other words, when the conductive particles according to the present invention are compressed, when the conductive particles are compressively displaced to more than 10% and not more than 25% of the particle diameter of the conductive particles before compression in the compression direction, . That is, it is preferable that the compressive displacement of the conductive particles causing cracks in the conductive layer is more than 10% and not more than 25%. For example, when the conductive particles are quite compressed, the conductive layer preferably partially cracks. In the conductive particles having such properties, not only the hardness at the initial stage of compression is sufficiently high but also cracks are generated when the particles are compressed appropriately. At the time of connecting the electrodes, cracks are generated in the conductive layer at the stage where the conductive particles are suitably compressed, so that damage to the electrodes can be suppressed. As a result, the connection resistance between the electrodes in the obtained connection structure can be further reduced, and the reliability of conduction between the electrodes can be further improved.

In the case of the conductive particles according to the present invention, when the conductive particles according to the present invention are compressed while the compression modulus (5% K value) when compressed to 5% is 7000 N / mm 2 or more, It is preferable that cracks occur in the conductive layer when the conductive particles are compressed to 10% or more and 25% or less of the particle diameter. When the conductive particles having this preferable configuration are used for connection between the electrodes, the connection resistance between the electrodes can be further reduced.

When the compressive modulus (5% K value) when the conductive particles according to the present invention are compressed by 5% is 7000 N / mm < 2 > or more, the conductive particles in the initial stage of compression have sufficient hardness. Therefore, in the initial stage of the compression of the conductive particles at the time of connection between the electrodes, the oxide film on the surfaces of the electrodes and the conductive particles can be effectively removed. As a result, the electrode and the conductive layer in the conductive particle effectively contact each other, and the connection resistance between the electrodes can be further reduced.

On the other hand, when the electrodes were electrically connected using conductive particles having a compressive modulus (5% K value) of less than 7000 N / mm < 2 > at the time of 5% compression, the compressive modulus ) Of 7000 N / mm < 2 > or more, the exclusion of the oxide film on the surfaces of the electrodes and the conductive particles tends to be lowered, and the connection resistance between the electrodes tends to be higher .

From the viewpoint of further lowering the connection resistance between the electrodes, the 5% K value is more preferably 8000 N / mm 2 or more, and still more preferably 9000 N / mm 2 or more. The upper limit of the 5% K value is not particularly limited. The 5% K value may be, for example, 15000 N / mm 2 or less, or 10000 N / mm 2 or less.

The compression modulus (5% K value) can be measured as follows.

The conductive particles are compressed using a micro compression tester under the conditions of a smooth indenter end face of a circumference (diameter 50 탆, made of diamond), a compression rate of 2.6 mN / sec, and a maximum test load of 10 gf. The load value N and the compression displacement (mm) at this time are measured. From the obtained measured values, the above-mentioned compressive modulus can be obtained by the following formula. As the micro-compression tester, for example, "Fisher Scope H-100" manufactured by Fisher Company is used.

K value (N / mm 2) = (3/2 ^1/2 ) · F · S ^-3/2 · R ^-1/2

F: load value (N) when the conductive particles are 5% compressively deformed

S: Compressive displacement (mm) when conductive particles were 5% compressively deformed

R: radius of conductive particle (mm)

The compressive modulus (10% K value and 5% K value) shows the hardness of the conductive particles in a universal and quantitative manner. By using the compressive elastic modulus, the hardness of the conductive particles can be quantitatively and univocally displayed.

From the viewpoint of further lowering the connection resistance between the electrodes, the compression displacement at which cracks are generated in the conductive layer is more preferably 12% or more, and more preferably 20% or less.

Hereinafter, the present invention will be clarified by explaining specific embodiments and examples of the present invention with reference to the drawings.

1 is a cross-sectional view showing a conductive particle according to a first embodiment of the present invention.

1, the conductive particles 1 have base particles 2, a conductive layer 3, a plurality of core materials 4, and a plurality of insulating materials 5.

The conductive layer 3 is disposed on the surface of the base particle 2. The conductive layer (3) comprises nickel and boron and the above metal component (M). The conductive layer 3 is a nickel-boron-tungsten / molybdenum conductive layer. The conductive particle (1) is a coated particle in which the surface of the base particle (2) is covered with the conductive layer (3).

The conductive particles (1) have a plurality of projections (1a) on its surface. The conductive layer 3 has a plurality of projections 3a on its outer surface. A plurality of core materials (4) are disposed on the surface of the base particles (2). A plurality of core materials (4) are embedded in the conductive layer (3). The core material 4 is disposed inside the projections 1a and 3a. The conductive layer 3 covers a plurality of core materials 4. The outer surface of the conductive layer 3 is raised by the plurality of core materials 4 and the projections 1a and 3a are formed.

The conductive particles (1) have an insulating material (5) arranged on the outer surface of the conductive layer (3). At least a part of the outer surface of the conductive layer (3) is covered with an insulating material (5). The insulating material 5 is formed of a material having an insulating property and is insulating particles. As such, the conductive particles according to the present invention may have an insulating material disposed on the outer surface of the conductive layer. However, the conductive particles according to the present invention do not necessarily have an insulating material.

2 is a cross-sectional view showing a conductive particle according to a second embodiment of the present invention.

2 includes a base particle 2, a second conductive layer 12 (another conductive layer), a conductive layer 13 (a first conductive layer), a plurality of core materials 4, and a plurality of Of insulating material (5).

In the conductive particles (1) and the conductive particles (11), only the conductive layer is different. That is, in the conductive particles 1, a conductive layer having a one-layer structure is formed, whereas the conductive particles 11 have a two-layered structure in which the second conductive layer 12 and the conductive layer 13 are formed.

The conductive layer 13 is disposed on the surface of the base particle 2. A second conductive layer 12 (another conductive layer) is disposed between the base particle 2 and the conductive layer 13. [ Therefore, the second conductive layer 12 is disposed on the surface of the base particle 2, and the conductive layer 13 is disposed on the surface of the second conductive layer 12. The conductive layer 13 includes nickel, boron, and tungsten. The conductive layer 13 has a plurality of projections 13a on its outer surface. The conductive particles 11 have a plurality of projections 11a on their surfaces.

3 is a cross-sectional view showing a conductive particle according to a third embodiment of the present invention.

The conductive particles 21 shown in FIG. 3 have base particles 2 and a conductive layer 22. The conductive layer 22 is disposed on the surface of the base particle 2. The conductive layer 22 comprises nickel, boron, and the metal component M described above.

The conductive particles 21 do not have a core material. The conductive particles 21 have no projections on the surface. The conductive particles 21 are spherical. The conductive layer 22 has no projections on its surface. Thus, the conductive particles according to the present invention may have no projections or be spherical. Further, the conductive particles 21 have no insulating material. However, the conductive particles 21 may have an insulating material disposed on the surface of the conductive layer 22.

In the conductive particles (1, 11, 21), the content of nickel is 70 wt% or more and 99.9 wt% or less and the content of the metal component M is 0.1 By weight or more and 30% by weight or less. It is also preferable that the conductive layers 3, 13 and 22 contain phosphorus or the conductive layers 3 and 13 and 22 contain phosphorus and the content of phosphorus Is preferably less than 1% by weight.

The 5% K value of the conductive particles (1, 11, 21) is preferably 7000 N / mm < 2 > When the conductive particles (1, 11, 21) are compressed, the conductive particles (1, 11, 21) exceed 10% of the particle diameters of the conductive particles (1, 11, 21) It is preferable that cracks occur in the conductive layers 3, 13, and 22 when they are compressively displaced to 25% or less. That is, in the conductive particles (1, 11, 21), when the particle diameter of the conductive particles (1, 11, 21) before compression in the compression direction is X, It is preferable that cracks occur in the conductive layers 3, 13, 22 when the particle diameter is 0.75X or more and less than 0.90X. For example, when the diameter of the conductive particles (1, 11, 21) before compression in the compression direction is 5 m, the conductive particles (1, 11, 21) It is preferable that cracks occur in the conductive layers 3, 13, and 22 when the particle diameters of the conductive layers 3, 13, and 21 become 3.75 탆 or more and less than 4.5 탆. In the conductive particles 11, not only the conductive layer 13 but also the second conductive layer 12 may be cracked.

Further, the "crack" represents the first (first) crack in the conductive layer. Therefore, in the conductive particles 1, 11, 21 according to the present embodiment, when the conductive particles 1, 11, 21 having the conductive layers 3, 13, 22 without the crack are compressed, 13, 22 are cracked when they are compressed and displaced by more than 10% and not more than 25% of the particle diameters of the conductive particles (1, 11, 21) before compression in the compression direction .

The measurement of the compressive displacement in which cracks are generated in the conductive layers 3, 13, 22 is specifically carried out as follows. In Fig. 5, the conductive particles 21 are used.

As shown in FIG. 5, the conductive particles 21 are placed on the sample stage 71. (Diameter: 50 탆, made of diamond) was pressed as a compression member 72 using a micro compression tester (Fisher Scope H-100 manufactured by Fisher Company) under conditions of a compression rate of 0.33 mN / sec and a maximum test load of 10 mN , The smooth end face 72a of the compression member 72 is lowered in the direction shown by the arrow A toward the conductive particles 21. Then, And the conductive particles 21 are compressed by the smoothing end face 72a. Compression continues until a crack 22a is partially formed in the conductive layer 22 of the conductive particles 21. [ In the case of the conductive particles (1, 11), the same measurement is made.

5 shows a state in which the cracks 22a are formed in the conductive layer 22 in the upper and lower portions of the conductive particles 21, the position where cracks are generated in the conductive layer is not particularly limited.

When the conductive particles are compressed as described above, when the conductive particles are compressively displaced by more than 10% of the particle diameter of the conductive particles before compression in the compression direction, cracks are generated in the conductive layer, It is preferable that cracks are generated in the conductive layer by displacement.

When the compression load value and the compression displacement are measured while the conductive particles are compressed, the relationship between the compression load value and the compression displacement becomes, for example, as shown in Fig. In Fig. 6, compression starts from point A0, and a crack is generated in the conductive layer at point A1. As the conductive layer cracks, the compressive displacement (particle diameter) of the conductive particles in the compression direction changes, and the compressive displacement moves from point A1 to point A2. When compressive load is applied to the conductive particles during compression, when the conductive layer cracks, the conductive particles are compressed with a relatively small compressive load. Therefore, the compression member having a compressive load applied to the conductive particles moves and compresses the conductive particles Displacement (particle diameter) changes.

In Fig. 6, the slope of the line from the point A0 to the point A1 is relatively large. When the 5% K value of the conductive particles 21 is 7000 N / mm 2 or more and the conductive particles 21 are relatively hard, the slope of the line from the A 0 point to the A1 point becomes large.

[Substrate Particle]

Examples of the base particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles and metal particles. The base particles are preferably base particles excluding metal particles, and are preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles.

The base particles are preferably resin particles formed by a resin. When the electrodes are connected using the conductive particles, the conductive particles are disposed between the electrodes and then compressed to compress the conductive particles. When the base particles are resin particles, the conductive particles are liable to be deformed at the time of pressing, and the contact area between the conductive particles and the electrodes becomes large. This improves the reliability of conduction between the electrodes.

Examples of the resin for forming the resin particles include polyolefin resin, acrylic resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, Polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, polyetheretherketone, polyether sulfone, divinylbenzene polymer, and divinylbenzene copolymer. Examples of the divinylbenzene-based copolymer and the like include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylate copolymer. It is preferable that the resin for forming the resin particles is a polymer obtained by polymerizing at least one polymerizable monomer having a plurality of ethylenically unsaturated groups in order that the hardness of the base particles can be easily controlled within a preferable range.

Examples of the inorganic substance for forming the inorganic particles include silica and carbon black. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

When the base particles are metal particles, examples of the metal for forming the metal particles include silver, copper, nickel, silicon, gold and titanium.

The particle diameter of the base particles is preferably 0.1 占 퐉 or more, more preferably 1 占 퐉 or more, further preferably 1.5 占 퐉 or more, particularly preferably 2 占 퐉 or more, preferably 1000 占 퐉 or less, more preferably 500 Mu m or less, still more preferably 300 mu m or less, still more preferably 50 mu m or less, particularly preferably 30 mu m or less, and most preferably 5 mu m or less. When the particle diameter of the base particles is not less than the above lower limit, the contact area between the conductive particles and the electrode becomes larger, so that the reliability of the connection between the electrodes is further increased, and the connection resistance between the electrodes connected via the conductive particles is further lowered. Further, when the conductive layer is formed on the surface of the base particles by electroless plating, it is difficult to coagulate, and it is difficult to form the agglomerated conductive particles. If the particle diameter is below the upper limit, the conductive particles are sufficiently compressed, the connection resistance between the electrodes is further lowered, and the distance between the electrodes becomes smaller. The particle size of the base particles indicates a diameter when base particles are spherical, and indicates a maximum diameter when base particles are not spherical.

Particle diameter of the base particles is particularly preferably 2 탆 or more and 5 탆 or less. If the particle diameter of the base particles is within the range of 2 to 5 占 퐉, the distance between the electrodes becomes small, and even if the thickness of the conductive layer is made thick, small conductive particles can be obtained.

[Conductive layer]

The conductive particles according to the present invention are disposed on the surface of the base particle and have a conductive layer X containing at least one metal component M of nickel, boron, tungsten and molybdenum. The conductive layer X may be directly laminated on the surface of the base particle or may be disposed on the surface of the base particle via another conductive layer or the like. Further, another conductive layer may be disposed on the surface of the conductive layer X. It is preferable that no other conductive layer is disposed on the outer surface of the conductive layer X. And the outer surface of the conductive particles is preferably the conductive layer X containing nickel. When the electrodes are connected by the conductive particles having the conductive layer X containing nickel, the connection resistance is further lowered.

The conductive layer X includes at least one metal component M of nickel, boron, tungsten, and molybdenum. The conductive layer X is a nickel-boron-tungsten / molybdenum conductive layer. The conductive layer X preferably includes nickel, boron, and tungsten, and preferably includes nickel, boron, and molybdenum, and preferably includes nickel, boron, tungsten, and molybdenum. The conductive layer X may be a nickel-boron-tungsten conductive layer or a nickel-boron-molybdenum conductive layer. The metal component M preferably includes tungsten, and preferably includes molybdenum, and preferably includes tungsten and molybdenum.

In the conductive layer X, nickel, boron and the metal component M can be alloyed. In the conductive layer X, nickel and boron may be alloyed, or nickel and the metal component M may be alloyed, and boron and the metal component M may be alloyed. Further, in the conductive layer X, in addition to nickel, boron and the above-described metal component M, chromium and tellurium can be used.

Further, in the conductive particles having a nickel conductive layer not containing both tungsten and molybdenum, the hardness of the nickel conductive layer containing neither tungsten nor molybdenum tends to be relatively low in the initial stage of compression. Therefore, when the electrodes are connected to each other, the effect of eliminating the oxide film on the surfaces of the electrodes and the conductive particles is reduced, and the effect of lowering the connection resistance tends to become smaller.

On the other hand, if the thickness of the nickel electroconductive layer not containing both tungsten and molybdenum is made thick so as to further attain the effect of lowering the connection resistance or suitable for applications in which a large current flows, There is a tendency to get hurt. As a result, the reliability of conduction between the electrodes in the connection structure tends to be lowered.

On the other hand, since the conductive layer X includes at least one metal component M of nickel, tungsten, and molybdenum, it is easy to set the 5% K value to the lower limit or more. Further, when the conductive particles are compressed to 10% or more and 25% or less of the particle diameter of the conductive particles before compression in the compression direction, it is easy to cause a crack to be generated in the conductive layer X. Cracks are generated when they are appropriately compressed, so that damage to the electrodes is more difficult to occur, and the connection resistance between the electrodes is further lowered.

Further, since the conductive layer X includes nickel and at least one kind of metallic component M of tungsten and molybdenum, the conductive layer X has a suitable hardness. Therefore, when the conductive particles X are compressed to connect the electrodes, An indentation suitable for the electrode can be formed. The indentations formed on the electrodes are concave portions of the electrodes in which the conductive particles are pressed against the electrodes.

The conductive layer X preferably contains nickel as a main component. From the viewpoint of effectively lowering the initial connection resistance between the electrodes, the greater the content of nickel in the entire 100 wt% of the conductive layer X, the better. Therefore, the content of nickel in the entire 100 wt% of the conductive layer X is preferably 50 wt% or more, more preferably 60 wt% or more, still more preferably 70 wt% or more, still more preferably 75 wt% %, More preferably at least 80 wt.%, Particularly preferably at least 85 wt.%, Even more particularly preferably at least 90 wt.%, Most preferably at least 95 wt.%. The content of nickel in the entire 100 wt% of the conductive layer X may be 97 wt% or more, 97.5 wt% or more, and 98 wt% or more. If the nickel content is lower than the lower limit, the connection resistance between the electrodes is further lowered. Further, when the surface of the electrode or the conductive layer has a small amount of oxidation film, the connection resistance between the electrodes tends to be lower as the content of nickel is larger.

The upper limit of the nickel content can be appropriately changed depending on the content of boron, the content of the metal component M, and the like. The content of nickel in the entire 100 wt% of the conductive layer X is preferably 99.9 wt% or less, more preferably 99.85 wt% or less, still more preferably 99.7 wt% or less, particularly preferably 99.45 wt% or less.

In the conductive particles having a nickel conductive layer not containing boron, the nickel conductive layer containing no boron is relatively soft at the initial stage of compression, and the effect of eliminating the oxide film on the surfaces of the electrodes and the conductive particles at the time of connection between the electrodes is small So that the effect of lowering the connection resistance tends to become smaller. In addition, the conductive layer may contain phosphorus instead of boron. In the conductive particles having a conductive layer containing nickel and phosphorus, the effect of excluding the oxide film on the surfaces of the electrodes and the conductive particles is reduced, and the effect of lowering the connection resistance tends to become smaller.

On the other hand, in order to further attain the effect of lowering the connection resistance, or to increase the thickness of the conductive layer not including boron or the thickness of the conductive layer including nickel and phosphorus , The member to be connected or the substrate tends to be scratched by the conductive particles. As a result, the reliability of conduction between the electrodes in the connection structure tends to be lowered.

On the other hand, since the conductive layer X includes boron, it is easy to set the 5% K value to the lower limit or more. Further, when the conductive particles are compressed to 10% or more and 25% or less of the particle diameter of the conductive particles before compression in the compression direction, it is easy to cause a crack to be generated in the conductive layer X. Further, it is further easier to make the 5% K value to the lower limit or higher by including the nickel, boron and the metal component M in the conductive layer X. [ Further, when the conductive particles are compressed to not less than 10% and not more than 25% of the particle diameter of the conductive particles before compression in the compression direction, it is easy to cause a more appropriate crack to be generated by the conductive layer X. Cracks are generated when they are appropriately compressed, so that damage to the electrodes is more difficult to occur, and the connection resistance between the electrodes is further lowered.

In addition, since the conductive layer X includes boron, the conductive layer X has a suitable hardness, so that the damage of the electrode is less likely to occur, and the connection resistance between the electrodes is further lowered. In addition, since the conductive layer X includes boron, the conductive layer X has a suitable hardness, so that when the conductive particles are compressed to connect the electrodes, an indentation suitable for the electrode can be formed.

In particular, since the conductive layer X includes nickel, boron, and the metal component M, it is possible to achieve a high compressive modulus. Therefore, the electrodes and the oxide film on the surfaces of the conductive particles can be effectively removed at the initial stage of compression of the conductive particles at the time of connection between the electrodes, and at the time of the connection between the electrodes, Cracks are generated, so that damage to the electrodes can be suppressed. As a result, it is possible to lower the connection resistance between the electrodes in the obtained connection structure, and to improve the reliability of the conduction between the electrodes.

The content of boron in the entire 100 wt% of the conductive layer X is preferably 0.01 wt% or more, more preferably 0.05 wt% or more, further preferably 0.1 wt% or more, preferably 5 wt% By weight, preferably not more than 4% by weight, more preferably not more than 3% by weight, particularly preferably not more than 2.5% by weight, most preferably not more than 2% by weight. If the boron content is lower than the above lower limit, the conductive layer X becomes more rigid, and the oxide film on the surface of the electrode and the conductive particle can be removed more effectively, so that the connection resistance between the electrodes can be further reduced. If the content of boron is less than the upper limit, the content of nickel and the metal component M becomes relatively large, so that the connection resistance between the electrodes becomes low.

The surface of the conductive layer X including nickel and boron has a high magnetic property and tends to be easily connected between adjacent electrodes in the transverse direction due to the influence of the conductive particles agglomerated by magnetism when the electrodes are electrically connected to each other . Since the conductive layer X contains nickel and boron and the metal component M, the magnetic properties of the surface of the conductive layer X are considerably lowered. Therefore, aggregation of a plurality of conductive particles can be suppressed. Therefore, when the electrodes are electrically connected to each other, it is possible to suppress the connection between the electrodes adjacent to each other in the transverse direction by the agglomerated conductive particles. That is, it is possible to further prevent a short circuit between adjacent electrodes.

In addition, since the conductive layer X includes the metal component M, the conductive layer X has a suitable hardness, so that when the conductive particles are compressed to connect the electrodes, an indentation suitable for the electrode can be formed. In addition, since the conductive layer X includes at least one of tungsten and molybdenum or contains boron, the conductive layer X becomes quite hard. As a result, the connection structure in which the electrodes are connected by the conductive particles is impacted The conduction defect is less likely to occur. That is, the impact resistance of the connection structure can be increased.

The content of the metal component M (the total content of tungsten and molybdenum) in the entire 100 wt% of the conductive layer X is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, still more preferably 0.2 wt% More preferably at least 0.5% by weight, even more preferably at least 1% by weight, particularly preferably at least 5% by weight and most preferably at least 10% by weight. If the content of the metal component M is lower than the lower limit, the hardness of the outer surface of the conductive layer becomes higher. Therefore, when an oxide film is formed on the surface of the electrode or the conductive layer, the oxide film on the electrode and the surface of the conductive particle can be effectively removed, the resin component between the electrode and the conductive particle can be effectively removed, As the resistance decreases, the impact resistance of the resulting connection structure increases. If the content of the metal component M is lower than the lower limit, the magnetism of the outer surface of the conductive layer X becomes weak, so that the plurality of conductive particles are hardly aggregated. Therefore, the short circuit between the electrodes can be effectively suppressed.

The upper limit of the content of the metal component M in the entire 100 wt% of the conductive layer X can be appropriately changed depending on the content of nickel and boron. The content of the metal component M in the entire 100 wt% of the conductive layer X is preferably 40 wt% or less, more preferably 30 wt% or less, still more preferably 25 wt% or less, particularly preferably 20 wt% % Or less.

When the conductive layer X contains tungsten, the content of tungsten in the entire 100 wt% of the conductive layer X is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, still more preferably Is more preferably at least 0.2 wt%, more preferably at least 0.5 wt%, even more preferably at least 1 wt%, particularly preferably at least 5 wt%, most preferably at least 10 wt%, preferably at most 40 wt% More preferably not more than 30% by weight, still more preferably not more than 25% by weight, particularly preferably not more than 20% by weight. In the case where the conductive layer X contains molybdenum, the content of molybdenum in the entire 100 wt% of the conductive layer X is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, still more preferably 0.2 More preferably at least 0.5 wt.%, Even more preferably at least 1 wt.%, Particularly preferably at least 5 wt.%, Most preferably at least 10 wt.%, Preferably at most 40 wt.%, By weight, preferably not more than 30% by weight, more preferably not more than 25% by weight, particularly preferably not more than 20% by weight.

From the viewpoint of effectively lowering the initial connection resistance between the electrodes, the total content of the nickel and the metal component M in the entire 100 wt% of the conductive layer X is preferably as large as possible. Therefore, the total content of nickel and the metal component M in the entire 100 wt% of the conductive layer X is preferably at least 75.1 wt%, more preferably at least 80.1 wt%, and still more preferably at least 85.1 wt% , Particularly preferably not less than 90.1 wt%, and most preferably not less than 95.1 wt%. The total content of nickel and the metal component M in the entire 100 wt% of the conductive layer X may be 97.1 wt% or more, 97.6 wt% or more, and 98.1 wt% or more.

In view of further lowering the connection resistance between the electrodes, the conductive layer X does not contain phosphorus, or the conductive layer X contains phosphorus and the content of phosphorus in the entire 100 wt% of the conductive layer X is less than 1 wt% . In view of further lowering the connection resistance between the electrodes, the conductive layer X does not contain phosphorus, or the conductive layer X contains phosphorus and the content of phosphorus in the entire 100 wt% of the conductive layer X is less than 0.5 wt% More preferable. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the content of phosphorus in the entire 100 wt% of the conductive layer X is more preferably 0.3 wt% or less, more preferably 0.1 wt% or less. Since the content of phosphorus is equal to or less than the upper limit, it is possible to more effectively exclude the oxide film on the surfaces of the electrodes and the conductive particles at the time of connection between the electrodes. As a result, the connection resistance between the electrodes can be reduced. Further, since the resin component between the electrode and the conductive particle can be effectively removed, the connection resistance between the electrodes is further lowered. It is particularly preferable that the conductive layer X does not contain phosphorus because the connection resistance between the electrodes is considerably low.

Particularly, when the conductive layer X contains the metal component M and the content of phosphorus is not more than the upper limit and the conductive layer X further has projections on the outer surface, the oxide film on the surface of the electrode and the conductive particles is more effectively excluded The resin component between the electrode and the conductive particles can be more effectively excluded, and the connection resistance can be further reduced.

In addition, since the conductive layer X includes the metal component M and the content of phosphorus is not more than the upper limit, the conductive layer X becomes quite hard. As a result, even if a shock is given to the connection structure in which the electrodes are connected by the conductive particles So that conduction failure is less likely to occur. That is, the impact resistance of the connection structure can be increased.

The method for measuring the respective contents of nickel, boron, tungsten, molybdenum and phosphorus in the conductive layer X can be various known analytical methods and is not particularly limited. As the measuring method, an absorption analysis method or a spectrum analysis method can be mentioned. In the above-mentioned absorption spectrometry, a frame absorption spectrophotometer and an electric heating spectrophotometer can be used. Examples of the spectrum analysis include plasma emission analysis and plasma ion mass spectrometry.

When measuring the respective contents of nickel, boron, tungsten, molybdenum and phosphorus in the conductive layer X, it is preferable to use an ICP emission spectrometer. Commercially available products of the ICP emission spectrometer include ICP emission spectrometers manufactured by HORIBA. An ICP-MS analyzer can be used to measure the respective contents of nickel, boron, tungsten, molybdenum, and phosphorus in the conductive layer X.

The metal for forming the other conductive layer (second conductive layer) is not particularly limited. Examples of the metal include gold, silver, copper, palladium, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, Tungsten, and alloys thereof. Examples of the metal include indium tin oxide (ITO) and solder. Among them, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is more preferable because the connection resistance between the electrodes is further lowered. The metal constituting the other conductive layer preferably includes nickel.

The method for forming the conductive layer (the other conductive layer and the conductive layer X) on the surface of the base particles is not particularly limited. Examples of the method of forming the conductive layer include a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method in which paste containing metal powder or metal powder and a binder is applied to the surface of base particles or other conductive layer And the like. Among them, the electroless plating method is preferable because the formation of the conductive layer is simple. Examples of the physical deposition method include vacuum deposition, ion plating and ion sputtering.

The particle diameter of the conductive particles is preferably 0.1 mu m or more, more preferably 0.5 mu m or more, still more preferably 1 mu m or more, particularly preferably 2 mu m or more, preferably 1,000 mu m or less, more preferably 500 Mu m or less, still more preferably 300 mu m or less, still more preferably 100 mu m or less, further preferably 50 mu m or less, particularly preferably 30 mu m or less, still more preferably 20 mu m or less, 5 탆 or less. When the diameter of the conductive particles is not less than the lower limit and not more than the upper limit, when the electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrode becomes sufficiently large, It becomes difficult to be formed. Further, the distance between the electrodes connected via the conductive particles does not become excessively large, and the conductive layer becomes difficult to peel off from the surface of the base particles.

The particle diameter of the conductive particles when used in a conductive material such as an anisotropic conductive material is preferably 0.5 占 퐉 or more, more preferably 1 占 퐉 or more, preferably 100 占 퐉 or less, and more preferably 20 占 퐉 or less. When the diameter of the conductive particles is not less than the lower limit and not more than the upper limit, when the electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrode becomes sufficiently large, It becomes difficult to be formed. Further, the distance between the electrodes connected through the conductive particles is not excessively large, and the conductive layer is hard to peel off from the surface of the base particles.

The particle diameter of the conductive particles indicates the diameter when the conductive particles are spherical, and the maximum diameter when the conductive particles are not spherical.

The thickness of the conductive layer X is preferably 0.005 탆 or more, more preferably 0.01 탆 or more, further preferably 0.05 탆 or more, preferably 1 탆 or less, and more preferably 0.3 탆 or less. When the thickness of the conductive layer X is not less than the lower limit and not more than the upper limit, sufficient conductivity is obtained and the conductive particles are not excessively hardened, and the conductive particles are sufficiently deformed at the time of connection between the electrodes.

In the case where the conductive layer has a laminated structure of two or more layers, the thickness of the conductive layer X is preferably 0.001 탆 or more, more preferably 0.01 탆 or more, more preferably 0.05 탆 or more, preferably 0.5 탆 or less Is not more than 0.3 mu m, and more preferably not more than 0.1 mu m. When the thickness of the conductive layer X is not less than the lower limit and not more than the upper limit, the covering by the conductive layer X can be made uniform, and the connection resistance between the electrodes becomes sufficiently low.

In the case where the conductive layer has a laminated structure of two or more layers, the total thickness of the conductive layer including the conductive layer X is preferably 0.001 탆 or more, more preferably 0.01 탆 or more, still more preferably 0.05 탆 or more, Is preferably 0.1 占 퐉 or more, preferably 1 占 퐉 or less, more preferably 0.5 占 퐉 or less, still more preferably 0.3 占 퐉 or less, further preferably 0.1 占 퐉 or less. When the total thickness of the conductive layer is not less than the lower limit and not more than the upper limit, the covering by the entire conductive layer can be made uniform and the connection resistance between the electrodes becomes sufficiently low.

The thickness of the conductive layer X is particularly preferably 0.05 탆 or more and 0.5 탆 or less. It is particularly preferable that the base particles have a particle diameter of 2 占 퐉 or more and 5 占 퐉 or less while the thickness of the conductive layer X is 0.05 占 퐉 or more and 0.5 占 퐉 or less. The thickness of the conductive layer X is most preferably 0.05 탆 or more and 0.3 탆 or less. It is most preferable that the particle size of the base particles is not less than 2 탆 and not more than 5 탆 and the thickness of the conductive layer X is not less than 0.05 탆 and not more than 0.3 탆. When satisfying these preferable thicknesses of the conductive layer X and the particle size of the base particles, the conductive particles can be suitably used for applications in which a large current flows. In addition, when the conductive particles are compressed to connect the electrodes, damage to the electrodes can be further suppressed.

The thickness of the conductive layer X and the total thickness of the conductive layer can be measured by observing the cross section of the conductive particles using, for example, a transmission electron microscope (TEM).

Examples of the method for controlling the content of nickel, tungsten, molybdenum, boron and phosphorus in the conductive layer X include a method of controlling the pH of the nickel plating liquid when forming the conductive layer X by electroless nickel plating, A method of adjusting the concentration of the boron-containing reducing agent when forming the conductive layer X by plating, a method of adjusting the concentration of tungsten in the nickel plating solution, a method of adjusting the concentration of molybdenum in the nickel plating solution, and a method of adjusting the concentration of nickel salt in the nickel plating solution And the like.

In the method of forming by electroless plating, generally a catalytic process and an electroless plating process are performed. Hereinafter, an example of a method of forming an alloy plating layer containing at least one of nickel, tungsten, and molybdenum and boron on the surface of resin particles by electroless plating will be described.

In the catalytic step, a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the resin particles.

As a method for forming the catalyst on the surface of the resin particle, there is a method in which resin particles are added to a solution containing, for example, palladium chloride and tin chloride, and then the surface of the resin particle is activated with an acid solution or an alkali solution, And the surface of the resin particle is activated by a solution containing a reducing agent to precipitate palladium on the surface of the resin particle And the like. As the reducing agent, a boron-containing reducing agent is preferably used. However, a phosphorus-containing reducing agent such as sodium hypophosphite may be used as the reducing agent.

In the electroless plating process, a nickel plating bath containing the nickel salt, at least one of the tungsten-containing compound and the molybdenum-containing compound, and the boron-containing reducing agent is used. By immersing the resin particles in the nickel plating bath, nickel can be precipitated on the surface of the resin particles formed on the surface of the catalyst, so that nickel, boron, and the conductive layer containing the metal component M can be formed.

Examples of the tungsten-containing compound include tungsten boride and sodium tungstate.

Examples of the molybdenum-containing compound include molybdenum boride and sodium molybdate.

Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, and potassium borohydride.

The conductive particles according to the present invention preferably have projections on their surfaces. The conductive layer including the conductive layer X preferably has projections on its outer surface, and the conductive layer X preferably has projections on its outer surface. Often, an oxide film is formed on the surface of an electrode connected by conductive particles. In many cases, an oxide film is formed on the surface of the conductive layer of the conductive particles. By using the conductive particles having protrusions, the conductive particles are arranged between the electrodes and then pressed, whereby the oxide film is effectively removed by the protrusions. Therefore, the electrode and the conductive particle can be contacted more reliably, and the connection resistance between the electrodes can be lowered. In addition, when the conductive particles have an insulating material on the surface or when the conductive particles are dispersed in the binder resin and used as a conductive material, the resin between the conductive particles and the electrode can be effectively removed by the protrusions of the conductive particles. Therefore, the conduction reliability between the electrodes becomes high

It is preferable that the projections are plural. The protrusions on the outer surface of the conductive layer per one conductive particle are preferably three or more, more preferably five or more. The upper limit of the number of the projections is not particularly limited. The upper limit of the number of the projections can be appropriately selected in consideration of the particle diameter of the conductive particles and the like.

[Core material]

Since the core material is embedded in the conductive layer, it is easy for the conductive layer to have a plurality of projections on the outer surface. However, in order to form protrusions on the surfaces of the conductive particles and the conductive layer, the core material may not necessarily be used.

Examples of the method for forming the projections include a method in which a core material is attached to the surface of base particles and then a conductive layer is formed by electroless plating and a method in which a conductive layer is formed on the surface of base particles by electroless plating, And then a conductive layer is further formed by electroless plating.

As a method for disposing the core material on the surface of the base particles, for example, a conductive material serving as a core material is added to the dispersion of the base particles, and a core material is coated on the surface of the base particles, for example, And a method in which a conductive material as a core material is added to a container containing the base particles and a core material is adhered to the surface of the base particles by mechanical action by rotation of the container or the like. Among them, a method of integrating and adhering the core material on the surface of the base particles in the dispersion is preferable because it is easy to control the amount of the core material to be adhered.

Examples of the conductive material constituting the core material include conductive metals such as metals, oxides of metals, graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene. Among them, a metal is preferable because the conductivity can be increased and the connection resistance can be lowered more effectively. The core material is preferably a metal particle.

Examples of the metal include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, , A tin-copper alloy, a tin-silver alloy, and a tin-lead-silver alloy. Among them, nickel, copper, silver or gold is preferable. The metal constituting the core material may be the same as or different from the metal constituting the conductive layer. The metal constituting the core material preferably includes a metal constituting the conductive layer. The metal constituting the core material preferably includes nickel. The metal constituting the core material preferably includes nickel.

The shape of the core material is not particularly limited. The shape of the core material is preferably agglomerated. Examples of the core material include a lump of particles, an agglomerated mass agglomerated by a plurality of minute particles, and a lump of an irregular shape.

The average diameter (average particle diameter) of the core material is preferably 0.001 탆 or more, more preferably 0.05 탆 or more, preferably 0.9 탆 or less, and more preferably 0.2 탆 or less. If the average diameter of the core material is not less than the lower limit and not more than the upper limit, the connection resistance between the electrodes can be effectively lowered.

The " average diameter (average particle diameter) " of the core material indicates a number average diameter (number average particle diameter). The average diameter of the core material is obtained by observing 50 pieces of any core material with an electron microscope or an optical microscope and calculating an average value.

[Insulating material]

The conductive particles according to the present invention preferably include an insulating material disposed on the surface of the conductive layer. In this case, if conductive particles are used for connection between the electrodes, a short circuit between adjacent electrodes can be prevented. More specifically, when a plurality of conductive particles are in contact with each other, an insulating material exists between a plurality of electrodes, so that a short circuit between the electrodes adjacent to each other in the horizontal direction as well as between the upper and lower electrodes can be prevented. Further, at the time of connection between the electrodes, by pressurizing the conductive particles with the two electrodes, the insulating material between the conductive layer of the conductive particles and the electrodes can be easily excluded. Since the conductive particles have a plurality of protrusions on the outer surface of the conductive layer, the insulating material between the conductive layer of the conductive particles and the electrode can be easily removed.

Since the insulating material can be more easily removed at the time of pressing between the electrodes, the insulating material is preferably insulating particles.

Specific examples of the insulating resin that is a material of the insulating material include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins and water- .

Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid ester copolymer. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB-type styrene-butadiene block copolymer, SBS-type styrene-butadiene block copolymer and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. Examples of the thermosetting resin include an epoxy resin, a phenol resin, and a melamine resin. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, methylcellulose and the like. Among them, a water-soluble resin is preferable, and polyvinyl alcohol is more preferable.

Examples of the method of disposing the insulating material on the surface of the conductive layer include a chemical method and a physical or mechanical method. Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, and an emulsion polymerization method. Examples of the physical or mechanical methods include spray drying, hybridization, electrostatic deposition, spraying, dipping and vacuum deposition. Among them, a method of disposing the insulating material on the surface of the conductive layer through chemical bonding is preferable because the insulating material is difficult to desorb.

The average diameter (average particle diameter) of the insulating material can be appropriately selected in accordance with the particle diameter of the conductive particles and the use of the conductive particles. The average diameter (average particle diameter) of the insulating material is preferably 0.005 탆 or more, more preferably 0.01 탆 or more, preferably 1 탆 or less, and more preferably 0.5 탆 or less. When the average diameter of the insulating material is not less than the lower limit described above, the conductive layers in the plurality of conductive particles are less likely to contact each other when the conductive particles are dispersed in the binder resin. If the average diameter of the insulating particles is less than the upper limit, since the insulating material between the electrodes and the conductive particles is removed at the time of connection between the electrodes, there is no need to increase the pressure excessively, and there is no need to heat at a high temperature.

The " average diameter (average particle diameter) " of the insulating material indicates a number average diameter (number average particle diameter). The average diameter of the insulating material is obtained by using a particle size distribution measuring apparatus or the like.

[Conductive material]

The conductive material according to the present invention includes the above-described conductive particles and a binder resin. The conductive particles according to the present invention are preferably added to the binder resin and used as a conductive material. The conductive material according to the present invention is preferably an anisotropic conductive material.

The binder resin is not particularly limited. As the binder resin, a known insulating resin is used. Examples of the binder resin include a vinyl resin, a thermoplastic resin, a curable resin, a thermoplastic block copolymer and an elastomer. The binder resin may be used alone, or two or more thereof may be used in combination.

Examples of the vinyl resin include vinyl acetate resin, acrylic resin and styrene resin. Examples of the thermoplastic resin include a polyolefin resin, an ethylene-vinyl acetate copolymer, and a polyamide resin. Examples of the curable resin include an epoxy resin, a urethane resin, a polyimide resin and an unsaturated polyester resin. The curable resin may be a room-temperature curable resin, a thermosetting resin, a photo-curable resin, or a moisture-curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenation product of styrene-butadiene-styrene block copolymer, and styrene-isoprene- Hydrogenated products, and the like. Examples of the elastomer include styrene-butadiene copolymer rubber, and acrylonitrile-styrene block copolymer rubber.

The conductive material may contain, in addition to the conductive particles and the binder resin, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, Flame retardant, and the like.

As a method of dispersing the conductive particles in the binder resin, conventionally known dispersion methods can be used, and there is no particular limitation. Examples of the method for dispersing the conductive particles in the binder resin include a method in which the conductive particles are added to the binder resin and then kneaded and dispersed with a planetary mixer or the like; a method in which the conductive particles are dispersed in water or an organic solvent And then kneading the mixture with a planetary mixer or the like, and a method of diluting the binder resin with water or an organic solvent, adding the conductive particles, Kneading with a kneader mixer or the like and dispersing them.

The conductive material according to the present invention can be used as a conductive paste and a conductive film. When the conductive material according to the present invention is used as an adhesive on a film such as a conductive film, a film-like adhesive containing no conductive particles may be laminated on the adhesive on the film containing the conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

The content of the binder resin in 100 wt% of the conductive material is preferably 10 wt% or more, more preferably 30 wt% or more, still more preferably 50 wt% or more, particularly preferably 70 wt% Is 99.99% by weight or less, and more preferably 99.9% by weight or less. When the content of the binder resin is not less than the lower limit and not higher than the upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the member to be connected connected by the conductive material is further enhanced.

The content of the conductive particles in 100 wt% of the conductive material is preferably not less than 0.01 wt%, more preferably not less than 0.1 wt%, preferably not more than 40 wt%, more preferably not more than 20 wt% By weight is not more than 10% by weight. When the content of the conductive particles is not less than the lower limit and not more than the upper limit, the reliability of the conduction between the electrodes is further enhanced.

[Connection structure]

The connection structure can be obtained by using the conductive particles of the present invention or by connecting the members to be connected using a conductive material containing the conductive particles and the binder resin.

The connection structure includes a first connection object member, a second connection object member, and a connection portion connecting the first and second connection object members, and the connection portion is formed by the conductive particles of the present invention , Or a connection structure formed by a conductive material containing the conductive particles and a binder resin. When conductive particles are used, the connection portion itself is conductive particles. That is, the first and second connection target members are connected by the conductive particles. It is preferable that the conductive material used for obtaining the connection structure is an anisotropic conductive material.

4 is a front sectional view schematically showing a connection structure using conductive particles according to a first embodiment of the present invention.

The connecting structure 51 shown in Fig. 4 has a connecting portion 51 connecting the first connection target member 52, the second connection target member 53 and the first and second connection target members 52 and 53 54). The connection portion 54 is formed by curing a conductive material containing the conductive particles 1. [ In Fig. 4, the conductive particles 1 are shown schematically for convenience of illustration.

The first connection target member 52 has a plurality of electrodes 52b on its upper surface 52a (surface). The second connection target member 53 has a plurality of electrodes 53b on the lower surface 53a (surface). The electrode 52b and the electrode 53b are electrically connected by one or a plurality of conductive particles 1. [ Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1. [

The manufacturing method of the connection structure is not particularly limited. An example of a manufacturing method of the connection structure is a method of arranging the conductive material between the first connection target member and the second connection target member and obtaining a laminate and then heating and pressing the laminate . The pressure of the pressurization is about 9.8 x 10 ⁴ to 4.9 x 10 ⁶ Pa. The heating temperature is about 120 to 220 占 폚.

Specifically, examples of the member to be connected include electronic parts such as a semiconductor chip, a capacitor and a diode, and a circuit substrate such as a printed substrate, a flexible printed substrate, and a glass substrate. The conductive material is preferably a conductive material for connecting electronic components. The conductive material is a paste-like conductive paste, and is preferably coated on the member to be connected in a paste state.

Examples of the electrode formed on the member to be connected include a metal electrode such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a molybdenum electrode, and a tungsten electrode. When the connection target member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. When the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of the metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al and Ga.

Hereinafter, the present invention will be described in detail by way of examples and comparative examples. The present invention is not limited to the following examples.

(Example 1)

Divinylbenzene copolymer resin particles (Micro Pearl SP-203, product of Sekisui Chemical Co., Ltd.) having a particle diameter of 3.0 탆 were prepared.

10 parts by weight of the resin particles were dispersed in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic dispersing machine, and the solution was filtered to take out the resin particles. Subsequently, the resin particles were added to 100 parts by weight of a 1 wt% solution of dimethylamine borane to activate the surface of the resin particles. The surface-activated resin particles were sufficiently washed with water and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

A nickel plating solution (pH 8.5) containing 0.23 mol / L of nickel sulfate, 0.92 mol / L of dimethylamine borane, 0.5 mol / L of sodium citrate and 0.01 mol / L of sodium tungstate was prepared.

While stirring the obtained suspension at 60 占 폚, the nickel plating solution was slowly dropped into the suspension, and electroless nickel plating was carried out. Thereafter, the suspension was filtered to take out the particles, washed with water and dried to obtain conductive particles having a nickel-boron-tungsten conductive layer (thickness: 0.1 mu m) disposed on the surface of the resin particles.

(Example 2)

Conductive particles in which a nickel-boron-tungsten conductive layer (thickness: 0.1 mu m) was disposed on the surface of the resin particles were obtained in the same manner as in Example 1 except that the sodium tungstate concentration was changed to 0.12 mol / L.

(Example 3)

Conductive particles in which a nickel-boron-tungsten conductive layer (thickness: 0.1 mu m) was disposed on the surface of the resin particles were obtained in the same manner as in Example 1 except that the sodium tungstate concentration was changed to 0.23 mol / L.

(Example 4)

Conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 1 except that the concentration of sodium tungstate was changed to 0.35 mol / L.

(Example 5)

A nickel-boron-tungsten conductive layer (thickness: 0.1) was formed on the surface of the resin particles in the same manner as in Example 1, except that the concentration of dimethylamine borane was changed to 2.76 mol / L and the concentration of sodium tungstate was changed to 0.35 mol / Mu m) were disposed.

(Example 6)

(1) palladium deposition process

Divinylbenzene resin particles (Micropearl SP-205, manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 5.0 mu m were prepared. The resin particles were etched and washed with water. Next, resin particles were added to 100 mL of a palladium catalyst solution containing 8 wt% of palladium catalyst and stirred. Thereafter, it was filtered and washed. Resin particles were added to a 0.5 wt% dimethylamine borane solution having a pH of 6 to obtain resin particles having palladium attached thereto.

(2) Core material deposition process

The resin particles having palladium attached thereto were stirred and dispersed in 300 ml of ion-exchanged water for 3 minutes to obtain a dispersion. Subsequently, 1 g of a metallic nickel particle slurry (average particle diameter 100 nm) was added to the above dispersion for 3 minutes to obtain resin particles having a core material attached thereto.

(3) Electroless nickel plating process

In the same manner as in Example 1, conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained.

(Example 7)

Conductive particles in which a nickel-boron-tungsten conductive layer (thickness: 0.1 mu m) was disposed on the surface of the resin particles were obtained in the same manner as in Example 6 except that the sodium tungstate concentration was changed to 0.35 mol / L.

(Example 8)

(1) Preparation of insulating particles

In a 1000 mL separable flask equipped with a four-neck seperable cover, a stirrer, a three-way cock, a cooling tube, and a temperature probe, 100 mmol of methyl methacrylate and 100 mmol of N, N, N-trimethyl- A monomer composition comprising 1 mmol of oxyethylammonium chloride and 1 mmol of 2,2'-azobis (2-amidinopropane) dihydrochloride was weighed with ion-exchanged water so that the solid content became 5% by weight, The mixture was stirred at 200 rpm, and polymerization was carried out at 70 캜 for 24 hours in a nitrogen atmosphere. After completion of the reaction, the resultant was lyophilized to obtain insulating particles having an ammonium group on the surface and having an average particle diameter of 220 nm and a CV value of 10%.

The insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

10 g of the conductive particles obtained in Example 6 were dispersed in 500 ml of ion-exchanged water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. The mixture was filtered with a 3 탆 mesh filter, then further washed with methanol, and dried to obtain conductive particles with insulating particles.

As a result of observation by a scanning electron microscope (SEM), only one coating layer composed of insulating particles was formed on the surface of the conductive particles. The coated area of the insulating particles (i.e., the projected area of the particle diameter of the insulating particles) with respect to the area of 2.5 占 퐉 from the center of the conductive particles was calculated by image analysis, and the coating rate was 30%.

(Example 9)

Conductive particles in which a nickel-boron-tungsten conductive layer (thickness: 0.1 mu m) was disposed on the surface of the resin particles were obtained in the same manner as in Example 1 except that the sodium tungstate concentration was changed to 0.46 mol / L.

(Example 10)

A nickel-boron-tungsten conductive layer (having a thickness of 0.1 占 퐉) was formed on the surface of the resin particle in the same manner as in Example 1, except that the concentration of dimethylamine borane was changed to 4.60 mol / L and the concentration of sodium tungstate was changed to 0.23 mol / ) Was disposed on the conductive particles.

(Comparative Example 1)

The procedure of Example 1 was repeated except that 0.92 mol / L of dimethylamine borane in the nickel plating solution was changed to 0.5 mol / L of sodium hypophosphite to form a conductive layer containing nickel, tungsten, and phosphorus on the surface of the resin particles ) Was disposed on the conductive particles. The content of phosphorus in the entire conductive layer of 100% by weight was 8.9% by weight.

(Comparative Example 2)

Conductive particles were obtained in the same manner as in Example 1 except that 0.01 mol / L of sodium tungstate in the nickel plating solution was not used, and a conductive layer (thickness 0.1 mu m) containing nickel and boron was disposed on the surface of the resin particles.

(Example 11)

Divinylbenzene copolymer resin particles (Micro Pearl SP-203, product of Sekisui Chemical Co., Ltd.) having a particle diameter of 3.0 탆 were prepared.

10 parts by weight of the resin particles were dispersed in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic dispersing machine, and the solution was filtered to take out the resin particles. Subsequently, the resin particles were added to 100 parts by weight of a 1 wt% solution of dimethylamine borane to activate the surface of the resin particles. The surface-activated resin particles were sufficiently washed with water and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

A nickel plating solution (pH 8.5) containing 0.23 mol / L of nickel sulfate, 0.92 mol / L of dimethylamine borane, 0.5 mol / L of sodium citrate and 0.01 mol / L of sodium molybdate was prepared.

While stirring the obtained suspension at 60 占 폚, the nickel plating solution was slowly dropped into the suspension, and electroless nickel plating was carried out. Thereafter, the suspension was filtered to take out the particles, washed with water and dried to obtain conductive particles having a nickel-boron-molybdenum conductive layer (thickness: 0.1 mu m) disposed on the surface of the resin particles.

(Example 12)

A conductive particle in which a nickel-boron-molybdenum conductive layer (thickness: 0.1 mu m) was disposed on the surface of the resin particle was obtained in the same manner as in Example 11 except that the concentration of sodium molybdate was changed to 0.12 mol / L.

(Example 13)

A conductive particle having a nickel-boron-molybdenum conductive layer (thickness of 0.1 mu m) was formed on the surface of the resin particle in the same manner as in Example 11 except that the sodium molybdate concentration was changed to 0.23 mol / L.

(Example 14)

Conductive particles having a nickel-boron-molybdenum conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 11 except that the concentration of sodium molybdate was changed to 0.35 mol / L.

(Example 15)

A nickel-boron-molybdenum conductive layer (having a thickness of 0.1 占 퐉) was formed on the surface of the resin particles in the same manner as in Example 11 except that the concentration of dimethylamine borane was changed to 2.76 mol / L and the concentration of sodium molybdate was changed to 0.35 mol / ) Was disposed on the conductive particles.

(Example 16)

(1) palladium deposition process

Divinylbenzene resin particles (Micropearl SP-205, manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 5.0 mu m were prepared. The resin particles were etched and washed with water. Next, resin particles were added to 100 mL of a palladium catalyzed solution containing 8 wt% of palladium catalyst and stirred. Thereafter, it was filtered and washed. Resin particles were added to a 0.5 wt% dimethylamine borane solution having a pH of 6 to obtain resin particles having palladium attached thereto.

(2) Core material deposition process

The resin particles having palladium attached thereto were stirred and dispersed in 300 ml of ion-exchanged water for 3 minutes to obtain a dispersion. Next, 1 g of metallic nickel particle slurry (average particle diameter 100 nm) was added to the above dispersion for 3 minutes to obtain resin particles having the core material attached thereto.

(3) Electroless nickel plating process

In the same manner as in Example 11, conductive particles having a nickel-boron-molybdenum conductive layer (having a thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained.

(Example 17)

A conductive particle having a nickel-boron-molybdenum conductive layer (thickness: 0.1 mu m) was formed on the surface of the resin particle in the same manner as in Example 16 except that the concentration of sodium molybdate was changed to 0.35 mol / L.

(Example 18)

(1) Preparation of insulating particles

In a 1000 mL separable flask equipped with a four-neck seperable cover, a stirrer, a three-way cock, a cooling tube and a temperature probe, 100 mmol of methyl methacrylate and 100 mmol of N, N, N-trimethyl- A monomer composition containing 1 mmol of ethylammonium chloride and 1 mmol of 2,2'-azobis (2-amidinopropane) dihydrochloride was subjected to ion exchange water so as to have a solid content of 5% by weight, stirred at 200 rpm, Polymerization was carried out at 70 占 폚 in a nitrogen atmosphere for 24 hours. After completion of the reaction, the resultant was lyophilized to obtain insulating particles having an ammonium group on the surface and an average particle diameter of 220 nm and a CV value of 10%.

The insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

10 g of the conductive particles obtained in Example 16 were dispersed in 500 ml of ion-exchanged water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. The mixture was filtered with a 3 mu m mesh filter, then further washed with methanol and dried to obtain conductive particles having insulating particles adhered thereto.

As a result of observation by a scanning electron microscope (SEM), only one coating layer composed of insulating particles was formed on the surface of the conductive particles. The coated area of the insulating particles (i.e., the projected area of the particle diameter of the insulating particles) with respect to the area of 2.5 占 퐉 from the center of the conductive particles was calculated by image analysis, and the coating rate was 30%.

(Example 19)

A conductive particle having a nickel-boron-molybdenum conductive layer (thickness: 0.1 mu m) was formed on the surface of the resin particle in the same manner as in Example 11, except that the concentration of sodium molybdate was changed to 0.46 mol / L.

(Example 20)

A nickel-boron-molybdenum conductive layer (having a thickness of 0.1 占 퐉) was formed on the surface of the resin particles in the same manner as in Example 11 except that the concentration of dimethylamine borane was changed to 4.60 mol / L and the concentration of sodium molybdate was changed to 0.23 mol / ) Was disposed on the conductive particles.

(Comparative Example 3)

The procedure of Example 11 was repeated except that 0.92 mol / L of dimethylamine borane in the nickel plating solution was changed to 0.5 mol / L of sodium hypophosphite to prepare a conductive layer containing nickel, molybdenum and phosphorus ) Was disposed on the conductive particles. The content of phosphorus in the entire 100 wt% of the conductive layer was 9.5 wt%.

(Evaluation of Examples 1 to 20 and Comparative Examples 1 to 3)

(1) Compressive modulus of conductive particles (5% K value)

The compression elastic modulus (5% K value) of the obtained conductive particles was measured using a micro compression tester (Fisher Scope H-100 manufactured by Fisher Company).

(2) Crack generation test of conductive layer

The conductive particles were placed on the sample stage. (Diameter: 50 μm, made of diamond) was used as a compression member under the conditions of a compression rate of 0.33 mN / sec and a maximum test load of 10 mN using a micro compression tester (Fisher Scope H-100 manufactured by Fisher Company) And the smooth end face of the member was lowered toward the conductive particles. And the conductive particles were compressed by the smooth end faces. And compression was performed until a crack occurred in the conductive layer of the conductive particles. Tables 1 and 2 show the compressive displacements of the conductive particles having cracks in the conductive layer with respect to the particle diameters of the conductive particles before compression in the compression direction. With respect to the evaluation results of the compression displacement, the average values of the measured values of the three conductive particles are shown in Tables 1 and 2 below.

(3) the content of nickel, boron, phosphorus, tungsten and molybdenum in the entire 100 wt% of the conductive layer X

5 g of conductive particles was added to a mixture of 5 mL of 60% nitric acid and 10 mL of 37% hydrochloric acid to completely dissolve the conductive layer to obtain a solution. Using the obtained solution, the contents of nickel, boron, phosphorus, tungsten and molybdenum were analyzed by an ICP-MS analyzer (manufactured by Hitachi, Ltd.). In addition, the conductive layer in the conductive particles of the Examples did not contain phosphorus.

(4) Plating condition

The plating state of the obtained 50 conductive particles was observed by a scanning electron microscope. And the presence or absence of plating unevenness such as plating crack or plating peeling was observed. &Quot; Good " when the number of conductive particles whose plating unevenness was confirmed was 4 or less, and " Bad " when there were five or more conductive particles whose plating unevenness was confirmed.

(5) Coagulation state

10 parts by weight of a bisphenol A type epoxy resin ("Epicote 1009" manufactured by Mitsubishi Chemical Corporation), 40 parts by weight of an acrylic rubber (weight average molecular weight: about 800,000), 200 parts by weight of methyl ethyl ketone, , And 2 parts by weight of a silane coupling agent (" SH6040 ", manufactured by Dow Corning Toray Silicone Co., Ltd.) were mixed to prepare a conductive particle having a content of 3 wt% An anisotropic conductive material was obtained.

The obtained anisotropic conductive material was stored at 25 DEG C for 72 hours. After storage, it was evaluated whether or not the conductive particles agglomerated in the anisotropic conductive material had settled. &Quot; Good " when the agglomerated conductive particles did not settle, and " Bad " when the agglomerated conductive particles were settled.

(6) Connection resistance

Preparation of the connection structure:

10 parts by weight of a bisphenol A type epoxy resin ("Epicote 1009" manufactured by Mitsubishi Chemical Corporation), 40 parts by weight of an acrylic rubber (weight average molecular weight: about 800,000), 200 parts by weight of methyl ethyl ketone, , And 2 parts by weight of a silane coupling agent (" SH6040 ", manufactured by Dow Corning Toray Silicone Co., Ltd.) were mixed to prepare a conductive particle having a content of 3 wt% To obtain a resin composition.

The resulting resin composition was applied to a PET (polyethylene terephthalate) film having a thickness of 50 占 퐉 on which one side had been subjected to a release treatment and dried for 5 minutes by hot air at 70 占 폚 to prepare an anisotropic conductive film. The thickness of the obtained anisotropic conductive film was 12 占 퐉.

The resulting anisotropic conductive film was cut into a size of 5 mm x 5 mm. The cut anisotropic conductive film was placed on one side of a glass substrate (3 cm wide, 3 cm long) having an aluminum electrode (height 0.2 μm, L / S = 20 μm / 20 μm) To the center of the plate. Subsequently, a two-layer flexible printed substrate (2 cm wide, 1 cm long) having the same aluminum electrode was positioned and overlapped so that electrodes were bonded to each other. The laminate of the glass substrate and the two-layer flexible print substrate was subjected to thermocompression bonding under conditions of 10 N, 180 캜 and 20 seconds to obtain a connection structure. Further, a two-layer flexible printed substrate having an aluminum electrode directly formed on a polyimide film was used.

Measurement of connection resistance:

The connection resistance between the opposing electrodes of the resulting connection structure was measured by the four-terminal method. Further, the connection resistance was judged based on the following criteria.

[Criteria for judging connection resistance]

○○: Connection resistance is 2.0Ω or less

○: Connection resistance is more than 2.0Ω, 3.0Ω or less

?: Connection resistance is more than 3.0?, Not more than 5.0?

×: Connection resistance exceeded 5.0Ω

(7) Impact resistance

The impact resistance was evaluated by dropping the connection structure obtained in the above (6) evaluation of connection resistance from a position of 70 cm in height and confirming continuity. The case where the rate of increase of the resistance value from the initial resistance value was 50% or less was judged as " good ", and the case where the rate of increase of the resistance value from the initial resistance value exceeded 50% was judged as " defective ".

(8) Occurrence of indentation

(6) The electrodes formed on the glass substrate from the glass substrate side of the connection structure obtained in the above (6) evaluation of the connection resistance were observed, and the presence or absence of the indentation of the electrode in contact with the conductive particles was judged based on the following criterion Respectively. The presence or absence of the indentation of the electrode was observed with a differential interference microscope so that the electrode area became 0.02 mm 2, and the number of indentations per 0.02 mm 2 of the electrode was calculated. 10 arbitrary points were observed with a differential interference microscope, and the average value of the number of indentations per 0.02 mm < 2 >

[Criteria for determining whether indentation is formed]

○○: At least 25 indents per 0.02mm2 of electrode

○: Indentations per electrode 0.02 mm 2 were 20 or more and less than 25

?: Indentation of at least 5 pieces per 0.02 mm 2 of electrode, less than 20 pieces

X: Less than 5 indentations per 0.02 mm < 2 >

The results are shown in Tables 1 and 2 below.

The conductive particles of Examples 21 to 40 and Comparative Examples 4 to 6 were prepared separately from the conductive particles of Examples 1 to 20 and Comparative Examples 1 to 3.

(Example 21)

Divinylbenzene copolymer resin particles (Micro Pearl SP-203, product of Sekisui Chemical Co., Ltd.) having a particle diameter of 3.0 탆 were prepared.

10 parts by weight of the resin particles were dispersed in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic dispersing machine, and the solution was filtered to take out the resin particles. Subsequently, the resin particles were added to 100 parts by weight of a 1 wt% solution of dimethylamine borane to activate the surface of the resin particles. The surface-activated resin particles were sufficiently washed with water and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

A nickel plating solution (pH 8.5) containing 0.23 mol / L of nickel sulfate, 0.92 mol / L of dimethylamine borane, 0.5 mol / L of sodium citrate and 0.01 mol / L of sodium tungstate was prepared.

While stirring the obtained suspension at 60 占 폚, the nickel plating solution was slowly dropped into the suspension, and electroless nickel plating was carried out. Thereafter, the suspension was filtered to take out the particles, washed with water and dried to obtain conductive particles having a nickel-boron-tungsten conductive layer (thickness: 0.1 mu m) disposed on the surface of the resin particles.

(Example 22)

Conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 21 except that the sodium tungstate concentration was changed to 0.12 mol / L.

(Example 23)

Conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 21 except that the sodium tungstate concentration was changed to 0.23 mol / L.

(Example 24)

Conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 21 except that the sodium tungstate concentration was changed to 0.35 mol / L.

(Example 25)

A nickel-boron-tungsten conductive layer (having a thickness of 0.1 占 퐉) was formed on the surface of the resin particle in the same manner as in Example 21 except that the concentration of dimethylamine borane was changed to 2.76 mol / L and the concentration of sodium tungstate was changed to 0.35 mol / ) Was disposed on the conductive particles.

(Example 26)

(1) palladium deposition process

Divinylbenzene resin particles (Micropearl SP-205, manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 5.0 mu m were prepared. The resin particles were etched and washed with water. Next, resin particles were added to 100 mL of a palladium catalyzed solution containing 8 wt% of palladium catalyst and stirred. Thereafter, it was filtered and washed. Resin particles were added to a 0.5 wt% dimethylamine borane solution having a pH of 6 to obtain resin particles having palladium attached thereto.

(2) Core material deposition process

The resin particles having palladium attached thereto were stirred and dispersed in 300 ml of ion-exchanged water for 3 minutes to obtain a dispersion. Next, 1 g of metallic nickel particle slurry (average particle diameter 100 nm) was added to the above dispersion for 3 minutes to obtain resin particles having the core material attached thereto.

(3) Electroless nickel plating process

In the same manner as in Example 21, conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained.

(Example 27)

Conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 26 except that the concentration of sodium tungstate was changed to 0.35 mol / L.

(Example 28)

(1) Preparation of insulating particles

In a 1000 mL separable flask equipped with a four-neck seperable cover, a stirrer, a three-way cock, a cooling tube and a temperature probe, 100 mmol of methyl methacrylate and 100 mmol of N, N, N-trimethyl- A monomer composition containing 1 mmol of ethylammonium chloride and 1 mmol of 2,2'-azobis (2-amidinopropane) dihydrochloride was subjected to ion exchange water so as to have a solid content of 5% by weight, stirred at 200 rpm, Polymerization was carried out at 70 占 폚 in a nitrogen atmosphere for 24 hours. After completion of the reaction, the resultant was lyophilized to obtain insulating particles having an ammonium group on the surface and an average particle diameter of 220 nm and a CV value of 10%.

The insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

10 g of the conductive particles obtained in Example 26 were dispersed in 500 ml of ion-exchanged water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. The mixture was filtered with a 3 mu m mesh filter, then further washed with methanol and dried to obtain conductive particles having insulating particles adhered thereto.

As a result of observation by a scanning electron microscope (SEM), only one coating layer composed of insulating particles was formed on the surface of the conductive particles. The coated area of the insulating particles (i.e., the projected area of the particle diameter of the insulating particles) with respect to the area of 2.5 占 퐉 from the center of the conductive particles was calculated by image analysis, and the coating rate was 30%.

(Example 29)

Conductive particles having a nickel-boron-tungsten conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 21 except that the sodium tungstate concentration was changed to 0.46 mol / L.

(Example 30)

A nickel-boron-tungsten conductive layer (thickness: 0.1 占 퐉) was formed on the surface of the resin particles in the same manner as in Example 21 except that the concentration of dimethylamine borane was changed to 4.60 mol / L and the concentration of sodium tungstate was changed to 0.23 mol / ) Was disposed on the conductive particles.

(Comparative Example 4)

A conductive layer containing nickel, tungsten, and phosphorus (having a thickness of 0.1 μm) was formed on the surface of the resin particle in the same manner as in Example 21 except that 0.92 mol / L of dimethylamine borane in the nickel plating solution was changed to 0.5 mol / L of sodium hypophosphite. Mu m) were disposed. The content of phosphorus in the entire 100 wt% of the conductive layer was 8.7 wt%.

(Comparative Example 5)

Conductive particles were obtained in the same manner as in Example 21 except that 0.01 mol / L of sodium tungstate in the nickel plating solution was not used, and a conductive layer (thickness 0.1 mu m) containing nickel and boron was disposed on the surface of the resin particles.

(Example 31)

Divinylbenzene copolymer resin particles (Micro Pearl SP-203, product of Sekisui Chemical Co., Ltd.) having a particle diameter of 3.0 탆 were prepared.

10 parts by weight of the resin particles were dispersed in 100 parts by weight of an alkali solution containing 5% by weight of a palladium catalyst solution using an ultrasonic dispersing machine, and the solution was filtered to take out the resin particles. Subsequently, the resin particles were added to 100 parts by weight of a 1 wt% solution of dimethylamine borane to activate the surface of the resin particles. The surface-activated resin particles were sufficiently washed with water and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

A nickel plating solution (pH 8.5) containing 0.23 mol / L of nickel sulfate, 0.92 mol / L of dimethylamine borane, 0.5 mol / L of sodium citrate and 0.01 mol / L of sodium molybdate was prepared.

While stirring the obtained suspension at 60 占 폚, the nickel plating solution was slowly added dropwise to the suspension to conduct electroless nickel plating. Thereafter, the suspension was filtered to take out the particles, washed with water and dried to obtain conductive particles having a nickel-boron-molybdenum conductive layer (thickness: 0.1 mu m) disposed on the surface of the resin particles.

(Example 32)

Boron-molybdenum conductive layer (thickness: 0.1 mu m) was disposed on the surface of the resin particle was obtained in the same manner as in Example 31 except that the concentration of sodium molybdate was changed to 0.12 mol / L.

(Example 33)

Conductive particles having a nickel-boron-molybdenum conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 31 except that the sodium molybdate concentration was changed to 0.23 mol / L.

(Example 34)

A conductive particle having a nickel-boron-molybdenum conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particle was obtained in the same manner as in Example 31 except that the sodium molybdate concentration was changed to 0.35 mol / L.

(Example 35)

A nickel-boron-molybdenum conductive layer (thickness: 0.1 占 퐉) was formed on the surface of the resin particle in the same manner as in Example 31 except that the concentration of dimethylamine borane was changed to 2.76 mol / L and the concentration of sodium molybdate was changed to 0.35 mol / ) Was disposed on the conductive particles.

(Example 36)

(1) palladium deposition process

Divinylbenzene resin particles (Micropearl SP-205, manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 5.0 mu m were prepared. The resin particles were etched and washed with water. Next, resin particles were added to 100 mL of a palladium catalyzed solution containing 8 wt% of palladium catalyst and stirred. Thereafter, it was filtered and washed. Resin particles were added to a 0.5 wt% dimethylamine borane solution having a pH of 6 to obtain resin particles having palladium attached thereto.

(2) Core material deposition process

The resin particles having palladium attached thereto were stirred and dispersed in 300 ml of ion-exchanged water for 3 minutes to obtain a dispersion. Next, 1 g of metallic nickel particle slurry (average particle diameter 100 nm) was added to the above dispersion for 3 minutes to obtain resin particles having the core material attached thereto.

(3) Electroless nickel plating process

In the same manner as in Example 31, conductive particles having a nickel-boron-molybdenum conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained.

(Example 37)

Conductive particles having a nickel-boron-molybdenum conductive layer (thickness of 0.1 mu m) disposed on the surface of the resin particles were obtained in the same manner as in Example 36 except that the concentration of sodium molybdate was changed to 0.35 mol / L.

(Example 38)

(1) Preparation of insulating particles

In a 1000 mL separable flask equipped with a four-neck separable cover, a stirrer, a three-way cock, a cooling tube, and a temperature probe, 100 mmol of methyl methacrylate and 100 mmol of N, N, N-trimethyl-N-2-methacryloyloxy A monomer composition containing 1 mmol of ethylammonium chloride and 1 mmol of 2,2'-azobis (2-amidinopropane) dihydrochloride was subjected to ion exchange water so as to have a solid content of 5% by weight, stirred at 200 rpm, Polymerization was carried out at 70 占 폚 in a nitrogen atmosphere for 24 hours. After completion of the reaction, the resultant was lyophilized to obtain insulating particles having an ammonium group on the surface and an average particle diameter of 220 nm and a CV value of 10%.

The insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

10 g of the conductive particles obtained in Example 36 were dispersed in 500 ml of ion-exchanged water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. The mixture was filtered with a 3 mu m mesh filter, then further washed with methanol and dried to obtain conductive particles having insulating particles adhered thereto.

As a result of observation by a scanning electron microscope (SEM), only one coating layer composed of insulating particles was formed on the surface of the conductive particles. The coated area of the insulating particles (i.e., the projected area of the particle diameter of the insulating particles) with respect to the area of 2.5 占 퐉 from the center of the conductive particles was calculated by image analysis, and the coating rate was 30%.

(Example 39)

A conductive particle having a nickel-boron-molybdenum conductive layer (having a thickness of 0.1 mu m) disposed on the surface of the resin particle was obtained in the same manner as in Example 31 except that the concentration of sodium molybdate was changed to 0.46 mol / L.

(Example 40)

A nickel-boron-molybdenum conductive layer (having a thickness of 0.1 占 퐉) was formed on the surface of the resin particle in the same manner as in Example 31 except that the concentration of dimethylamine borane was changed to 4.60 mol / L and that of sodium molybdate was changed to 0.23 mol / ) Was disposed on the conductive particles.

(Comparative Example 6)

The procedure of Example 31 was repeated except that 0.92 mol / L of dimethylamine borane in the nickel plating solution was changed to 0.5 mol / L of sodium hypophosphite to prepare a conductive layer containing nickel, molybdenum and phosphorus on the surface of the resin particles ) Was disposed on the conductive particles. The content of phosphorus in the entire 100 wt% of the conductive layer was 9.5 wt%.

(Evaluation of Examples 21 to 40 and Comparative Examples 4 to 6)

(1) Compressive modulus of conductive particles (10% K value)

The compression elastic modulus (10% K value) of the obtained conductive particles was measured using a micro compression tester (Fisher Scope H-100 manufactured by Fisher Company).

(2) Compression recovery rate of conductive particles

The compression recovery rate when the obtained conductive particles were compressed by 30% was measured using a micro compression tester (Fisher Scope H-100 manufactured by Fisher Co.).

(3) the content of nickel, boron, phosphorus, tungsten and molybdenum in the entire 100 wt% of the conductive layer

5 g of conductive particles was added to a mixture of 5 mL of 60% nitric acid and 10 mL of 37% hydrochloric acid to completely dissolve the conductive layer to obtain a solution. Using the obtained solution, the contents of nickel, boron, phosphorus, tungsten and molybdenum were analyzed by an ICP-MS analyzer (manufactured by Hitachi, Ltd.). In addition, the conductive layer in the conductive particles of the Examples did not contain phosphorus.

(4) Plating condition

The plating state of the obtained 50 conductive particles was observed by a scanning electron microscope. And the presence or absence of plating unevenness such as plating crack or plating peeling was observed. &Quot; Good " when the number of conductive particles whose plating unevenness was confirmed was 4 or less, and " Bad " when there were five or more conductive particles whose plating unevenness was confirmed.

(5) Coagulation state

10 parts by weight of a bisphenol A type epoxy resin ("Epicote 1009" manufactured by Mitsubishi Chemical Corporation), 40 parts by weight of an acrylic rubber (weight average molecular weight: about 800,000), 200 parts by weight of methyl ethyl ketone, (Trade name: HX3941HP manufactured by Asahi Kasei Chemicals Co., Ltd.) and 2 parts by weight of a silane coupling agent (SH6040 manufactured by Toray Dow Corning Silicone Co., Ltd.) were mixed and dispersed so that the content of the conductive particles was 3 wt% An anisotropic conductive material was obtained.

The obtained anisotropic conductive material was stored at 25 DEG C for 72 hours. After storage, it was evaluated whether or not the conductive particles aggregated in the anisotropic conductive material were settled. &Quot; Good " when the agglomerated conductive particles did not settle, and " Bad " when the agglomerated conductive particles were settled.

(6) Initial connection resistance

Preparation of the connection structure:

10 parts by weight of a bisphenol A type epoxy resin ("Epicote 1009" manufactured by Mitsubishi Chemical Corporation), 40 parts by weight of an acrylic rubber (weight average molecular weight: about 800,000), 200 parts by weight of methyl ethyl ketone, , And 2 parts by weight of a silane coupling agent (" SH6040 " manufactured by Dow Corning Toray Silicone Co., Ltd.) were mixed to prepare a conductive particle having a content of 3 wt% To obtain a resin composition.

The obtained resin composition was applied to a PET (polyethylene terephthalate) film having a thickness of 50 占 퐉 on one side of which had been subjected to release treatment and dried by hot air at 70 占 폚 for 5 minutes to prepare an anisotropic conductive film. The thickness of the obtained anisotropic conductive film was 12 占 퐉.

The resulting anisotropic conductive film was cut into a size of 5 mm x 5 mm. The cut anisotropic conductive film was placed on one side of a glass substrate (3 cm wide, 3 cm long) having an aluminum electrode (height 0.2 μm, L / S = 20 μm / 20 μm) To the center of the plate. Subsequently, a two-layer flexible printed substrate (2 cm wide, 1 cm long) having the same aluminum electrode was positioned and aligned so that the electrodes overlapped with each other. The laminate of the glass substrate and the two-layer flexible print substrate was subjected to thermocompression bonding under conditions of 10 N, 180 캜 and 20 seconds to obtain a connection structure. Further, a two-layer flexible printed substrate having an aluminum electrode directly formed on a polyimide film was used.

Measurement of connection resistance:

The connection resistance between the opposing electrodes of the resulting connection structure was measured by the four-terminal method. The initial connection resistance was determined based on the following criteria.

[Criteria for judging connection resistance]

○○: Connection resistance is 2.0Ω or less

○: Connection resistance is more than 2.0Ω, 3.0Ω or less

?: Connection resistance is more than 3.0?, 4.0?

△△: Connection resistance exceeds 4.0Ω, 5.0Ω or less

×: Connection resistance exceeded 5.0Ω

(7) Connection resistance after high temperature and high humidity test

The connection structure obtained in the production of the above (6) connection structure was allowed to stand for 100 hours under the conditions of 85 캜 and 85% humidity. The connection resistance between the electrodes of the connection structure after left standing was measured by the four-terminal method, and the measured value obtained was regarded as the connection resistance after the high temperature and high humidity test. Also, the connection resistance after the high temperature and high humidity test was judged by the following criteria.

[Criteria for judging connection resistance]

○○: Connection resistance is 2.0Ω or less

○: Connection resistance is more than 2.0Ω, 3.0Ω or less

?: Connection resistance is more than 3.0?, 4.0?

△△: Connection resistance exceeds 4.0Ω, 5.0Ω or less

×: Connection resistance exceeded 5.0Ω

(8) Impact resistance

The impact resistance was evaluated by dropping the connection structure obtained in the above (6) production of the connection structure from a position of 70 cm in height and confirming continuity. The case where the rate of increase of the resistance value from the initial resistance value was 50% or less was judged as " good ", and the case where the rate of increase of the resistance value from the initial resistance value exceeded 50% was judged as " defective ".

(9) presence or absence of indentation

The electrodes formed on the glass substrate were observed from the side of the glass substrate of the connection structure obtained in the above (6) production of the connection structure using a differential interference microscope, and the presence or absence of indentation Respectively. The number of indentations per 0.02 mm < 2 > of the electrode was calculated by observing the presence or absence of indentation of the electrode with a differential interference microscope so that the electrode area became 0.02 mm < 2 >. 10 arbitrary points were observed with a differential interference microscope, and the average value of the number of indentations per 0.02 mm < 2 >

[Criteria for judging presence / absence of indentation formation]

○○: At least 25 indents per 0.02mm2 of electrode

○: Indentations per electrode 0.02 mm 2 were 20 or more and less than 25

?: Indentation of at least 5 pieces per 0.02 mm 2 of electrode, less than 20 pieces

X: indentation per 0.02 mm < 2 >

××: no indentation per 0.02 mm 2 of electrode

The results are shown in Tables 3 and 4 below.

1: conductive particles
1a: projection
2: Base particles
3: conductive layer
3a: projection
4: core material
5: Insulating material
11: conductive particles
11a:
12: second conductive layer
13: conductive layer
13a:
21: conductive particles
22: conductive layer
22a: Crack
51: connection structure
52: first connection object member
52a: upper surface
52b: electrode
53: second connection object member
53a: when
53b: electrode
54:
71:
72: compression member
72a: Smooth end face

Claims (14)

A base material particle,
And a conductive layer disposed on the surface of the base particle and containing at least one metal component selected from the group consisting of nickel, boron, tungsten, and molybdenum,
Wherein the conductive layer is disposed on the surface of the base particle and no other conductive layer is disposed on the outer surface of the conductive layer including nickel, boron, and the metal component,
Wherein the content of the metal component in the entire 100 wt% of the conductive layer disposed on the surface of the base particles is 0.01 wt% or more and 40 wt% or less. The conductive particle according to claim 1, wherein the content of boron in the entire 100 wt% of the conductive layer disposed on the surface of the base particles is 0.05 wt% or more and 4 wt% or less. The conductive particle according to claim 1 or 2, wherein the content of the metal component in the entire 100 wt% of the conductive layer disposed on the surface of the base particle is 0.1 wt% or more and 30 wt% or less. The conductive particle according to claim 1 or 2, wherein the content of the metal component in the entire 100 wt% of the conductive layer disposed on the surface of the base particle is more than 5 wt% and 30 wt% or less. 3. The conductive particle according to claim 1 or 2, wherein the metal component comprises tungsten. The conductive particle according to claim 1 or 2, wherein the compression modulus when the 10% compression deformation is not less than 5000 N / mm 2 and not more than 15000 N / mm 2. 3. The conductive particle according to claim 1 or 2, wherein the compression recovery rate is not less than 5% and not more than 70%. The conductive particle according to claim 1 or 2, wherein the metal component comprises molybdenum. 3. The method according to claim 1 or 2, wherein the conductive layer disposed on the surface of the base particle comprises nickel and molybdenum,
Wherein the content of nickel is 70% by weight or more and 99.9% by weight or less, and the content of molybdenum is 0.1% by weight or more and 30% by weight or less, among 100% by weight of the whole of the conductive layer disposed on the surface of the base particle. The electrophotographic photosensitive member according to claim 1, wherein when the conductive particles are compressed to 5% or more of the particle diameter of the conductive particles before compression in the compression direction and 25% or less in the compression direction, Wherein the conductive particles disposed on the surface are cracked. The conductive particle according to any one of claims 1, 2, and 10, wherein the thickness of the conductive layer disposed on the surface of the base particle is 0.05 占 퐉 or more and 0.5 占 퐉 or less. The conductive particle according to any one of claims 1, 2, and 10, wherein the conductive layer disposed on the surface of the base particle has protrusions on the outer surface. 11. A conductive material comprising the conductive particles according to any one of claims 1 to 10 and a binder resin. A first connecting object member, a second connecting object member, and a connecting portion connecting the first and second connecting object members,
Wherein the connecting portion is formed by the conductive particles according to any one of claims 1 to 10 or formed by a conductive material including the conductive particles and the binder resin.

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