WO2012002508A1

WO2012002508A1 - Conductive particle with insulative particles attached thereto, anisotropic conductive material, and connecting structure

Info

Publication number: WO2012002508A1
Application number: PCT/JP2011/065095
Authority: WO
Inventors: 茂雄真原
Original assignee: 積水化学工業株式会社
Priority date: 2010-07-02
Filing date: 2011-06-30
Publication date: 2012-01-05
Also published as: JP5060655B2; KR20130016387A; TW201207071A; JPWO2012002508A1; KR101321636B1; CN102959641A; CN102959641B; TWI498405B

Abstract

Disclosed is a conductive particle with insulative particles attached thereto, wherein the insulative particles do not come off the surface of the conductive particle so easily, and hence, reliability in the conductivity thereof can be increased upon connecting electrodes therewith. The conductive particle (1) with insulative particles attached thereto is provided with: a conductive particle (2) that has a conductive layer (12) on at least the surface thereof; and insulative particles (3) adhered to the surface of the conductive particle (2). The insulative particle (3) is comprised of an insulative particle body (5); and a layer (6) covering at least a portion of the surface of the insulative particle body (5), and which is formed of a high polymer. The insulative particle body (5) and the layer (6) are chemically bonded.

Description

Conductive particles with insulating particles, anisotropic conductive material, and connection structure

The present invention relates to, for example, conductive particles with insulating particles that can be used for electrical connection between electrodes, and an anisotropic conductive material and a connection structure using the conductive particles with insulating particles.

Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In these anisotropic conductive materials, conductive particles are dispersed in a binder resin.
The anisotropic conductive material is used for connection between an IC chip and a flexible printed circuit board, connection between an IC chip and a circuit board having an ITO electrode, and the like. For example, after disposing an anisotropic conductive material between the electrode of the IC chip and the electrode of the circuit board, these electrodes can be electrically connected by heating and pressing.

As an example of the conductive particles, the following Patent Document 1 discloses conductive with insulating particles having conductive particles and insulating particles fixed to the surface of the conductive particles and having adhesive properties. Particles are disclosed. The insulating particles include hard particles and a polymer resin layer covering the surfaces of the hard particles. Here, a physical / mechanical hybridization method is used as an immobilization method in order to immobilize the insulating particles on the surface of the conductive particles.

Patent Document 2 below includes conductive particles having a polar group on at least a part of a surface, and an insulating material that covers at least a part of the surface of the conductive particles and includes insulating particles. A conductive particle with insulating particles is disclosed. Specifically, the insulating material includes a polymer electrolyte that can adsorb the polar group, and inorganic oxide particles that can adsorb the polymer electrolyte. The inorganic oxide particles are insulating particles.

Special table 2007-537570 gazette JP 2008-120990 A

In the conventional conductive particles with insulating particles as described in

Patent Documents

1 and 2, the insulating particles are easily detached from the surface of the conductive particles. For example, when the conductive particles with insulating particles are dispersed in the binder resin, the insulating particles may be easily detached from the surface of the conductive particles.

In particular, as described in Patent Document 1, when a physical / mechanical hybridization method is used to immobilize the insulating particles on the surface of the conductive particles, the insulating particles are made of conductive particles. Easily detached from the surface.

An object of the present invention is to provide a conductive particle with an insulating particle that can improve the conduction reliability when the insulating particle is difficult to be detached from the surface of the conductive particle. It is to provide an anisotropic conductive material and a connection structure using conductive particles with insulating particles.

According to a wide aspect of the present invention, it comprises conductive particles having a conductive layer on at least a surface, and insulating particles attached to the surface of the conductive particles, and the insulating particles include an insulating particle body and A layer covering at least a part of the surface of the insulating particle body and formed of a polymer compound, and the insulating particle body and the layer are chemically bonded. Conductive particles with insulating particles are provided.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particle body is an inorganic particle.

In another specific aspect of the conductive particles with insulating particles according to the present invention, the layer is more flexible than the insulating particle body.

In still another specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particle main body having a reactive functional group on the surface and a polymer compound or a compound that becomes the polymer compound are used. The insulating particle body and the layer are chemically bonded by chemically bonding the layer formed of the polymer compound to the reactive functional group on the surface of the insulating particle body. The insulating particles are obtained.

In another specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles are friction by mixing using the insulating particle body and a polymer compound or a compound that becomes the polymer compound. Not formed.

In another specific aspect of the conductive particles with insulating particles according to the present invention, a conductive particle-containing liquid with insulating particles obtained by adding 3 parts by weight of conductive particles with insulating particles to 100 parts by weight of ethanol is 20 ° C. When the ultrasonic treatment is performed for 5 minutes under the condition of 38 kHz or 40 kHz, the residual ratio of the insulating particles obtained by the following formula (1) is 60 to 95%.

Residual rate of insulating particles (%) = (coverage after ultrasonic treatment / coverage before ultrasonic treatment) × 100 Equation (1)

In another specific aspect of the conductive particles with insulating particles according to the present invention, the coverage, which is the area of the portion covered with the insulating particles in the entire surface area of the conductive particles, is 40% or more. . The coverage is preferably over 50%.

The anisotropic conductive material according to the present invention includes conductive particles with insulating particles configured according to the present invention and a binder resin. The anisotropic conductive material according to the present invention is preferably an anisotropic conductive paste.

The connection structure according to the present invention includes a first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members, and the connection The portion is formed of conductive particles with insulating particles configured according to the present invention, or is formed of an anisotropic conductive material including the conductive particles with insulating particles and a binder resin.

In the conductive particles with insulating particles according to the present invention, the insulating particles attached to the surface of the conductive particles having at least the conductive layer on the surface are the insulating particle main body and at least the surface of the insulating particle main body. And a layer formed of a polymer compound that covers a part of the region, and since the insulating particle body and the layer are chemically bonded to each other, the insulating particle is exposed from the surface of the conductive particle. Can be prevented from unintentionally desorbing.

Accordingly, when the conductive particles with insulating particles according to the present invention are used to connect the electrodes, even if a plurality of conductive particles with insulating particles come into contact, the insulating particles are not insulated between adjacent conductive particles. Since particles exist, it is difficult to electrically connect adjacent electrodes that should not be connected. For this reason, the conduction | electrical_connection reliability between electrodes can be improved.

FIG. 1 is a cross-sectional view showing conductive particles with insulating particles according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing conductive particles with insulating particles according to the second embodiment of the present invention. FIG. 3 is a cross-sectional view showing conductive particles with insulating particles according to the third embodiment of the present invention. FIG. 4 is a front cross-sectional view schematically showing a connection structure using the conductive particles with insulating particles shown in FIG. FIG. 5 is a schematic diagram for explaining a method for evaluating the coverage. FIG. 6 is a cross-sectional view showing a conventional conductive particle with insulating particles using a hybridization method.

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

(Conductive particle body with insulating particles)
FIG. 1 is a sectional view showing conductive particles with insulating particles according to the first embodiment of the present invention.

1 includes the conductive particles 2 and a plurality of insulating particles 3 attached to the surface of the conductive particles 2.

The insulating particles 3 have an insulating particle body 5 and a layer 6 that covers the surface of the insulating particle body 5 and is formed of a polymer compound. The insulating particles 3 are made of an insulating material. The insulating particle body 5 and the layer 6 are chemically bonded. Specifically, the surface of the insulating particle body 5 and the inner surface of the layer 6 are chemically bonded.

The layer 6 covers the entire surface of the insulating particle body 5. Therefore, the layer 6 is disposed between the conductive particles 2 and the insulating particle main body 5. The layer 6 may be present so as to cover at least a part of the surface of the insulating particle main body, and may not cover the entire surface of the insulating particle main body. The layer 6 is preferably disposed between the conductive particles and the insulating particle main body.

The conductive particles 2 have base material particles 11 and a conductive layer 12 provided on the surface of the base material particles 11. The conductive layer 12 covers the surface of the base particle 11. The conductive particle 2 is a coated particle in which the surface of the base particle 11 is coated with the conductive layer 12. The conductive particles 2 have a conductive layer 12 on the surface.

FIG. 2 is a sectional view showing conductive particles with insulating particles according to the second embodiment of the present invention.

2 includes the conductive particles 22 and the plurality of insulating particles 3 attached to the surface of the conductive particles 22.

The conductive particles 22 have base material particles 11 and a conductive layer 31 provided on the surface of the base material particles 11. The conductive particles 22 have a plurality of core substances 32 on the surface of the substrate particles 11. The conductive layer 31 covers the base particle 11 and the core substance 32. By covering the core substance 32 with the conductive layer 31, the conductive particles 22 have a plurality of protrusions 33 on the surface. The surface of the conductive layer 31 is raised by the core substance 32, and a plurality of protrusions 33 are formed.

FIG. 3 is a sectional view showing conductive particles with insulating particles according to the third embodiment of the present invention.

The conductive particle 41 with insulating particles shown in FIG. 3 includes conductive particles 42 and a plurality of insulating particles 3 attached to the surface of the conductive particles 42.

The conductive particles 42 have base material particles 11 and a conductive layer 46 provided on the surface of the base material particles 11. The conductive layer 46 includes a first conductive layer 46a provided on the surface of the base particle 11 and a second conductive layer 46b provided on the surface of the first conductive layer 46a. The conductive particles 42 have a plurality of core substances 47 on the surface of the first conductive layer 46a. The second conductive layer 46 b covers the first conductive layer 46 a and the core substance 47. The substrate particles 11 and the core substance 47 are arranged with a space therebetween. A first conductive layer 46 a exists between the base particle 11 and the core substance 47. By covering the core substance 47 with the second conductive layer 46b, the conductive particles 42 have a plurality of protrusions 48 on the surface. The surfaces of the conductive layer 46 and the second conductive layer 46b are raised by the core material 47, and a plurality of protrusions 48 are formed.

In the

conductive particles

1, 21, 41 with insulating particles, the insulating particles 3 include an insulating particle body 5 and a layer 6 that covers the surface of the insulating particle body 5 and is formed of a polymer compound. Furthermore, the insulating particle body 5 and the layer 6 are chemically bonded. As a result, when the conductive particles with insulating

particles

1, 21, 41 are added to the binder resin and kneaded, the insulating particles 3 are less likely to be detached from the surfaces of the

conductive particles

2, 22, 42. Furthermore, when a plurality of conductive particles with insulating particles come into contact with each other, the insulating particles are hardly detached from the surfaces of the

conductive particles

2, 22, and 42. As a result, when the electrodes are connected using the conductive particles with insulating

particles

1, 21 and 41, leakage hardly occurs between adjacent electrodes that should not be connected. Further, the conductive particles with insulating

particles

1, 21, 41 can sufficiently ensure the continuity of the upper and lower electrodes to be connected.

In the

conductive particles

1, 21, 41 with insulating particles, the residual rate of the insulating particles 3 is preferably 60 to 95%. The residual rate of the insulating particles 3 is more preferably 70% or more, and more preferably 90% or less. When the residual ratio of the insulating particles 3 is equal to or more than the lower limit, the surfaces of the

conductive particles

2, 22, 42 are added when the

conductive particles

1, 21, 41 with insulating particles are added to the binder resin and kneaded. Insulating particles 3 are more difficult to detach from the electrode, and when electrodes are connected using conductive particles with insulating

particles

1, 21 and 41, more leakage occurs between adjacent electrodes that should not be connected. It becomes difficult. When the residual ratio of the insulating particles is less than or equal to the above upper limit, the high conductivity of the upper and lower electrodes to be connected can be sufficiently ensured.

The “residual ratio of the insulating particles” and the coverage, which is the area of the portion covered with the insulating particles in the entire surface area of the conductive particles, are obtained as follows.

Before the following ultrasonic treatment, 100 conductive particles with insulating particles were observed by observation with a scanning electron microscope (SEM), and the coverage X1 (%) of the conductive particles in the conductive particles with insulating particles was observed. (Also referred to as adhesion rate X1 (%)) is obtained. The said coverage is an area (projection area) of the part coat | covered with the insulating particle which occupies for the whole surface area of electroconductive particle.

Specifically, as shown in FIG. 5, when the conductive particles A with insulating particles are observed from one direction with a scanning electron microscope (SEM), the coverage is as follows. One insulating particle B1 present in the circle on the outer surface (outer peripheral edge) of the conductive layer, insulating property present on the circumference of the outer surface (outer peripheral edge) of the conductive layer of the conductive particle A with insulating particles The number of particles B2 is counted as 0.5, and is represented by the ratio of the projected area of the insulating particles to the projected area of the conductive particles A with insulating particles.

That is, the said coverage is represented by following formula (2).
Coverage (%) = (((number of insulating particles in circle) × 1 + (number of insulating particles on the circumference) × 0.5) × projection area of insulating particles) / (with insulating particles) Projected area of conductive particles) × 100 (2)

Next, 3 parts by weight of conductive particles with insulating particles are added to 100 parts by weight of ethanol to obtain a conductive particle-containing liquid with insulating particles. This conductive particle-containing liquid with insulating particles is subjected to ultrasonic treatment while being stirred for 5 minutes at 20 ° C. and 38 kHz or 40 kHz with a 400 W ultrasonic cleaner. After the ultrasonic treatment, 100 conductive particles with insulating particles are observed by observation with an SEM, and the portion of the conductive particles with insulating particles covered by the insulating particles occupying the entire surface area of the conductive particles. A coverage ratio X2 (%) (also referred to as an adhesion ratio X2 (%)) which is a projected area is obtained. The residual rate of the insulating particles is a value represented by the following formula (1) from the coverage X1 and the coverage X2.

Residual ratio of insulating particles (%) = (coverage ratio X2 after ultrasonic treatment / coverage ratio X1 before ultrasonic treatment) × 100 (1)

In order to appropriately expose the surface of the conductive particles, the coverage of the insulating particles is preferably 40% or more. The said coverage shows the area of the part coat | covered with the insulating particle which occupies for the whole surface area of electroconductive particle. When the coverage is equal to or higher than the lower limit, adjacent conductive particles are more difficult to contact. The coverage is preferably 90% or less, more preferably 80% or less, and most preferably 70% or less. When the coverage of the insulating particles is 70% or less, the insulating particles can be sufficiently eliminated without applying heat and pressure more than necessary when the electrodes are connected. The coverage may exceed 45%, may exceed 50%, may exceed 55%, and may exceed 60%.

In the case where the residual ratio of the insulating particles is 60 to 95%, in the conductive particles with insulating

particles

1, 21, 41, the insulating particles 3 are detached from the surfaces of the

conductive particles

2, 22, 42. It becomes difficult to separate. For example, when the

conductive particles

1, 21, 41 with insulating particles are added to the binder resin and kneaded, the insulating particles 3 are not easily detached from the surfaces of the

conductive particles

2, 22, 42. For this reason, when the

conductive particles

1, 21, 41 with insulating particles are used for the connection between the electrodes, the insulating particles 3 exist between the adjacent

conductive particles

2, 22, 42. It is difficult to electrically connect adjacent electrodes that should not be connected. Therefore, when the electrodes are connected using the conductive particles with insulating

particles

1, 21, 41, the conduction reliability can be improved.

The conductive particles with insulating particles have a layer formed of a polymer compound using a polymer compound or a compound that becomes a polymer compound so as to cover at least a part of the surface of the insulating particle body. It is preferably obtained through a step of forming and obtaining insulating particles and a step of attaching the insulating particles to the surface of the conductive particles having at least the surface of the conductive layer to obtain conductive particles with insulating particles.

From the viewpoint of further improving the conduction reliability between the electrodes and the insulation reliability, the variation coefficient of the particle diameter of the conductive particles with insulating particles is preferably 8% or less, more preferably 5% or less.

The coefficient of variation (CV value) is expressed by the following equation.
CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of particle diameter of conductive particles with insulating particles Dn: Average value of particle diameter of conductive particles with insulating particles

The compression elastic modulus of the conductive particles with insulating particles is preferably 1 GPa or more, more preferably 2 GPa or more, preferably 7 GPa or less, and more preferably 5 GPa or less.

The compression recovery rate of the conductive particles with insulating particles is preferably 20% or more, more preferably 30% or more, preferably 60% or less, more preferably 50% or less.

The compressive elastic modulus (10% K value) of the conductive particles with insulating particles at 20 ° C. is measured as follows.

Using a micro-compression tester, the conductive particles with insulating particles are compressed under the conditions of a compression rate of 0.33 mN / sec and a maximum test load of 20 mN on the end face of a diamond cylinder having a diameter of 50 μm. The load value (N) and compression displacement (mm) at this time are measured. From the measured value obtained, the compression elastic modulus can be obtained by the following formula. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.

10% K value (N / mm ² ) = (3/2 ^1/2 ) · F · S ⁻³ / ² · R ^−1/2
F: Load value (N) when conductive particles with insulating particles are compressively deformed by 10%
S: Compression displacement (mm) when conductive particles with insulating particles are 10% compressively deformed
R: radius of conductive particles with insulating particles (mm)

The above-described compression elastic modulus universally and quantitatively represents the hardness of the conductive particles with insulating particles. By using the compression modulus, the hardness of the conductive particles with insulating particles can be expressed quantitatively and uniquely.

The compression recovery rate can be measured as follows.

¡Sprinkle conductive particles with insulating particles on the sample stage. With respect to one dispersed conductive particle with insulating particles, a load is applied to the reversal load value (5.00 mN) in the center direction of the conductive particles with insulating particles using a micro compression tester. Thereafter, the load is gradually reduced to the load value for origin (0.40 mN). The load-compression displacement during this period is measured, and the compression recovery rate can be obtained from the following equation. The load speed is 0.33 mN / sec. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.

Compression recovery rate (%) = [(L1-L2) / L1] × 100
L1: Compressive displacement from the load value for the origin to the reverse load value when applying the load L2: Compressive displacement from the reverse load value to the load value for the origin when releasing the load

Hereinafter, details of the

conductive particles

2, 22, and 42 and details of the insulating particles 3 will be described.

[Conductive particles]
Conductive particles with insulating particles can be obtained by attaching the insulating particles to the surface of conductive particles having at least a conductive layer on the surface.

The conductive particles only need to have a conductive layer on at least the surface. The conductive particles may be conductive particles having base material particles and a conductive layer provided on the surface of the base material particles, or may be metal particles whose entirety is a conductive layer. Among these, from the viewpoint of reducing costs and increasing the flexibility of the conductive particles to increase the conduction reliability between the electrodes, the base particles and the conductive material provided on the surface of the base particles are used. Conductive particles having a layer are preferred.

Examples of the substrate particles include resin particles, inorganic particles, organic-inorganic hybrid particles, and metal particles.

The base material particles are preferably resin particles formed of a resin. When connecting the electrodes using the conductive particles with insulating particles, the conductive particles with insulating particles are compressed by placing the conductive particles with insulating particles between the electrodes and then pressing them. When the substrate particles are resin particles, the conductive particles are easily deformed during the above-described pressure bonding, and the contact area between the conductive particles and the electrode can be increased. For this reason, the conduction | electrical_connection reliability between electrodes can be improved.

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, and polyphenylene. Examples thereof include oxides, polyacetals, polyimides, polyamideimides, polyetheretherketones, and polyethersulfones. Since the hardness of the base particles can be easily controlled within a suitable range, the resin for forming the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. It is preferably a coalescence.

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

The metal for forming the conductive layer is not particularly limited. Furthermore, when the conductive particles are metal particles that are conductive layers as a whole, the metal for forming the metal particles is not particularly limited. Examples of the metal include gold, silver, copper, palladium, platinum, palladium, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, and silicon. And alloys thereof. Examples of the metal include tin-doped indium oxide (ITO) and solder. Especially, since the connection resistance between electrodes can be made still lower, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is more preferable.

Note that hydroxyl groups often exist on the surface of the conductive layer due to oxidation. In general, hydroxyl groups are present on the surface of a conductive layer formed of nickel by oxidation. Such a conductive layer having a hydroxyl group is easily chemically bonded to the insulating particles, for example, chemically bonded to the insulating particles having a hydroxyl group.

The conductive layer is formed of one layer. The conductive layer may be formed of a plurality of layers. That is, the conductive layer may have a stacked structure of two or more layers. When the conductive layer is formed of a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, a copper layer, or an alloy layer containing tin and silver, and is a gold layer. Is more preferable. When the outermost layer is these preferred conductive layers, the connection resistance between the electrodes can be further reduced. Moreover, when the outermost layer is a gold layer, the corrosion resistance can be further enhanced.

The method for forming the conductive layer on the surface of the substrate particles is not particularly limited. As a method for forming the conductive layer, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method of coating the surface of base particles with metal powder or a paste containing metal powder and a binder Etc. Especially, since formation of a conductive layer is simple, the method by electroless plating is preferable. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.

The average particle diameter of the conductive particles is preferably in the range of 0.5 to 100 μm. The average particle diameter of the conductive particles is more preferably 1 μm or more, and more preferably 20 μm or less. When the average particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, the contact area between the conductive particles and the electrodes is sufficiently large when the electrodes are connected using the conductive particles with insulating particles. In addition, it is difficult to form aggregated conductive particles when the conductive layer is formed. Further, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive layer is difficult to peel from the surface of the base material particles.

The “average particle size” of the conductive particles indicates a number average particle size. The average particle diameter of the conductive particles can be obtained by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

The thickness of the conductive layer is preferably in the range of 0.005 to 1 μm. The thickness of the conductive layer is more preferably 0.01 μm or more, and more preferably 0.3 μm or less. When the thickness of the conductive layer is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, and the conductive particles do not become too hard, and the conductive particles are sufficiently bonded at the time of connection between the electrodes. Can be deformed.

When the conductive layer is formed of a plurality of layers, the thickness of the outermost conductive layer is in the range of 0.001 to 0.5 μm, particularly when the outermost layer is a gold layer. It is preferable that A more preferable lower limit of the thickness of the outermost conductive layer is 0.01 μm, and a more preferable upper limit is 0.1 μm. When the thickness of the outermost conductive layer is not less than the above lower limit and not more than the above upper limit, the coating with the outermost conductive layer can be made uniform, corrosion resistance can be sufficiently enhanced, and the connection resistance between the electrodes can be increased. It can be made sufficiently low. Further, the thinner the gold layer when the outermost layer is a gold layer, the lower the cost.

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

The conductive particles preferably have protrusions on the surface of the conductive layer, and the protrusions are preferably plural. An oxide film is often formed on the surface of the electrode connected by the conductive particles with insulating particles. When the conductive particles with insulating particles having protrusions on the surface of the conductive layer are used, the oxide film can be effectively eliminated by the protrusions by disposing the conductive particles between the electrodes and pressing them. For this reason, an electrode and a conductive layer can be contacted still more reliably and the connection resistance between electrodes can be made low. Furthermore, when the electrodes are connected, the insulating particles between the conductive particles and the electrodes can be effectively eliminated by the protrusions of the conductive particles. For this reason, the conduction | electrical_connection reliability between electrodes can be improved.

As a method of forming protrusions on the surface of the conductive particles, a method of forming a conductive layer by electroless plating after attaching a core substance to the surface of the base particles, and by electroless plating on the surface of the base particles Examples of the method include forming a conductive layer, then attaching a core substance, and further forming a conductive layer by electroless plating.

As a method of attaching the core substance to the surface of the base particle, for example, a conductive substance that becomes the core substance is added to the dispersion of the base particle, and the core substance is applied to the surface of the base particle, for example, a fan. A method of accumulating and adhering by Delwars force, and adding a conductive substance as a core substance to a container containing base particles, and a core substance on the surface of the base particles by mechanical action such as rotation of the container And the like. Especially, since the quantity of the core substance to adhere is easy to control, the method of making a core substance accumulate and adhere on the surface of the base particle in a dispersion liquid is preferable.

The conductive particles may have a first conductive layer on the surface of the base particle, and may have a second conductive layer on the first conductive layer. In this case, a core substance may be attached to the surface of the first conductive layer. The core material is preferably covered with a second conductive layer. The thickness of the first conductive layer is preferably in the range of 0.05 to 0.5 μm. The conductive particles form a first conductive layer on the surface of the base particle, and then a core material is deposited on the surface of the first conductive layer, and then the first conductive layer and the core material are formed. It is preferably obtained by forming a second conductive layer on the surface.

Examples of the conductive substance constituting the core substance include metals, metal oxides, conductive nonmetals such as graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene. Among them, metal is preferable because conductivity can be increased.

Examples of the metal include gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and tin-lead. Examples thereof include alloys composed of two or more metals such as alloys, tin-copper alloys, tin-silver alloys, and tin-lead-silver alloys. Of these, 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 shape of the core substance is not particularly limited. The shape of the core substance is preferably a lump. Examples of the core substance include a particulate lump, an agglomerate in which a plurality of fine particles are aggregated, and an irregular lump.

[Insulating particles]
The insulating particles are particles having insulating properties. Insulating particles are smaller than conductive particles. When the electrodes are connected using conductive particles with insulating particles, the insulating particles can prevent a short circuit between adjacent electrodes. Specifically, when the conductive particles with a plurality of insulating particles are in contact with each other, there are insulating particles between the conductive particles in the conductive particles with a plurality of insulating particles. Short circuit between the electrodes adjacent in the lateral direction can be prevented. Note that the insulating particles between the conductive layer and the electrode can be easily excluded by pressurizing the conductive particles with insulating particles with the two electrodes when connecting the electrodes. In the case where protrusions are provided on the surface of the conductive particles, the insulating particles between the conductive layer and the electrode can be more easily eliminated. Furthermore, since the protruding portion facilitates contact with the electrode, connection reliability is improved.

Examples of the material constituting the insulating particles include an insulating resin and an insulating inorganic substance. As said insulating resin, the said resin quoted as resin for forming the resin particle which can be used as a base particle is mentioned. As said insulating inorganic substance, the said inorganic substance quoted as an inorganic substance for forming the inorganic particle which can be used as a base particle is mentioned.

Specific examples of the insulating resin that is the material of the insulating particles include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked thermoplastic resins, heat Examples thereof include curable resins and water-soluble resins.

Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic 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-acrylate 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. As said thermosetting resin, an epoxy resin, a phenol resin, a melamine resin, etc. are mentioned. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide, and methyl cellulose. Of these, water-soluble resins are preferable, and polyvinyl alcohol is more preferable.

From the viewpoint of further increasing the detachability of the insulating particles during thermocompression bonding, the insulating particle body is preferably inorganic particles. Examples of the inorganic particles include shirasu particles, hydroxyapatite particles, magnesia particles, zirconium oxide particles, and silica particles. From the viewpoint of further increasing the detachability of the insulating particles during thermocompression bonding, the insulating particle body is preferably silica particles. Examples of the silica particles include pulverized silica and spherical silica, and spherical silica is preferably used. The silica particles preferably have a functional group capable of chemical bonding such as a carboxyl group and a hydroxyl group on the surface, and more preferably have a hydroxyl group. Inorganic particles are relatively hard, especially silica particles are relatively hard. When conductive particles with insulating particles using such hard insulating particles as insulating particles are added to a binder resin and kneaded, the insulating particles are hard, so that the insulating particles are removed from the surface of the conductive particles. There is a tendency to detach easily. However, when the conductive particles with insulating particles according to the present invention are used, since the insulating particles have a layer formed of the above polymer compound, even if a hard insulating particle body is used, During kneading, it is possible to prevent the insulating particles having a hard insulating particle body from being detached.

The layer formed of the above polymer compound serves as a flexible layer, for example.

The polymer compound in the layer formed of the polymer compound or the compound that becomes the polymer compound by polymerization or the like is preferably a compound having a polymerizable reactive functional group. The polymerizable reactive functional group is preferably an unsaturated double bond. For example, a compound having an unsaturated double bond (a compound that becomes a polymer compound) may be subjected to a polymerization reaction on the surface of the insulating particle main body, and the reactive functional group on the surface of the polymer compound and the insulating particle main body. And may be reacted. Examples of the polymer compound or the compound to be the polymer compound include a compound having a (meth) acryloyl group, a compound having an epoxy group, and a compound having a vinyl group. From the viewpoint of suppressing detachment of the insulating particles from the surface of the conductive particles when dispersing the conductive particles with insulating particles, the polymer compound or the compound to be the polymer compound is (meth) It preferably has at least one reactive functional group selected from the group consisting of an acryloyl group, a glycidyl group and a vinyl group. Among these, from the viewpoint of further suppressing the detachment of the insulating particles, the polymer compound or the compound to be the polymer compound preferably has a (meth) acryloyl group.

Specific examples of the compound having the (meth) acryloyl group include methacrylic acid, hydroxyethyl acrylate, and ethylene glycol dimethacrylate.

Specific examples of the epoxy compound include bisphenol A type epoxy resin and resorcinol glycidyl ether.

Specific examples of the compound having a vinyl group include styrene and vinyl acetate.

The weight average molecular weight of the polymer compound is preferably 1000 or more. The upper limit of the weight average molecular weight of the polymer compound is not particularly limited, but the polymer compound preferably has a weight average molecular weight of 20000 or less. The weight average molecular weight indicates a value in terms of polystyrene measured by gel permeation chromatography (GPC).

The method for forming the layer formed of the polymer compound on the surface of the insulating particle body is not particularly limited. Using a polymer compound or a compound that becomes a polymer compound so as to cover at least a part of the surface of the insulating particle main body, a layer formed of the polymer compound is formed to obtain insulating particles. preferable. As an example of a method for forming a layer formed of the polymer compound, a compound having a reactive double bond and a hydroxyl group is formed on an insulating particle body having a reactive functional group such as a vinyl group on the surface. And a method of polymerizing on the surface. However, methods other than this forming method may be used.

The insulating particle body and the layer are chemically bonded. This chemical bond includes a covalent bond, a hydrogen bond, an ionic bond, a coordination bond, and the like. Of these, a covalent bond is preferable, and a chemical bond using a reactive functional group is preferable.

Examples of the reactive functional group that forms the chemical bond include a vinyl group, (meth) acryloyl group, silane group, silanol group, carboxyl group, amino group, ammonium group, nitro group, hydroxyl group, carbonyl group, and thiol group. Sulfonic acid group, sulfonium group, boric acid group, oxazoline group, pyrrolidone group, phosphoric acid group and nitrile group. Among these, a vinyl group and a (meth) acryloyl group are preferable.

From the viewpoint of further suppressing the detachment of the insulating particles and further improving the insulation reliability in the connection structure, it is possible to use an insulating particle body having a reactive functional group on the surface as the insulating particle body. preferable. From the viewpoint of further suppressing the detachment of the insulating particles and further improving the insulation reliability in the connection structure, the insulating particles subjected to surface treatment using a compound having a reactive functional group as the insulating particle main body. It is preferable to use a particle body. From the viewpoint of further suppressing the detachment of the insulating particles and further improving the insulation reliability in the connection structure, the insulating particle main body having a reactive functional group on the surface, the polymer compound, or the polymer compound And the layer formed of the polymer compound is chemically bonded to the reactive functional group on the surface of the insulating particle body using the compound to form the insulating particle body and the layer. It is preferable that the insulating particles that are chemically bonded are obtained.

Examples of the reactive functional group on the surface of the insulating particle body include a (meth) acryloyl group, a glycidyl group, a hydroxyl group, a vinyl group, and an amino group. The reactive functional group on the surface of the insulating particle body is at least one reactive functional group selected from the group consisting of a (meth) acryloyl group, a glycidyl group, a hydroxyl group, a vinyl group, and an amino group. Is preferred.

Examples of the compound (surface treatment substance) for introducing the reactive functional group onto the surface of the insulating particle body include a compound having a (meth) acryloyl group, a compound having an epoxy group, and a compound having a vinyl group. It is done.

As a compound (surface treatment substance) for introducing a vinyl group as the reactive functional group onto the surface of the insulating particle body, a silane compound having a vinyl group, a titanium compound having a vinyl group, and a vinyl group are used. The phosphoric acid compound etc. which have are mentioned. The surface treatment substance is preferably a silane compound having a vinyl group. Examples of the silane compound having a vinyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, and vinyltriisopropoxysilane.

As a compound (surface treatment substance) for introducing the (meth) acryloyl group which is the reactive functional group onto the surface of the insulating particle main body, a silane compound having a (meth) acryloyl group and a (meth) acryloyl group And a phosphoric acid compound having a (meth) acryloyl group. The surface treatment substance is also preferably a silane compound having a (meth) acryloyl group. Examples of the silane compound having a (meth) acryloyl group include (meth) acryloxypropyltriethoxysilane, (meth) acryloxypropyltrimethoxysilane, (meth) acryloxypropyltridimethoxysilane, and the like.

It is preferable that the insulating particles are not formed by friction by mixing using the insulating particle body and the polymer compound or the compound to be the polymer compound. Moreover, it is preferable that the surface of the insulating particle body is not covered with the layer using a hybridization method. When insulating particles are formed using friction by mixing or a hybridization method, the layer is easily detached from the surface of the insulating particle body. In addition, the fragments of the layer formed during kneading easily adhere to the surface of the insulating particles. For this reason, a layer or a fragment of the layer detached on the surface of the conductive layer of the conductive particles with insulating particles tends to adhere, and the conduction reliability in the connection structure tends to decrease. Therefore, from the viewpoint of further suppressing the detachment of the insulating particles and further increasing the insulation reliability and conduction reliability in the connection structure, it is preferable that the insulating particles are not formed by friction due to mixing. It is preferable not to use a hybridization method.

When the insulating particles are obtained, the amount of the polymer compound or the compound that becomes the polymer is preferably 30 parts by weight or more, more preferably 50 parts by weight or more, preferably 100 parts by weight of the insulating particle body. Is 500 parts by weight or less, more preferably 300 parts by weight or less. A favorable layer can be formed as the usage-amount of the said high molecular compound is more than the said minimum and below the said upper limit.

Examples of specific production conditions for the layer formed of the polymer compound include the following production conditions.

First, in 100 to 500 parts by weight of a solvent such as water, 1 to 3 parts by weight of an insulating particle body having a reactive functional group on the surface, and 0.1 to 20 parts by weight of a compound having a reactive double bond and a hydroxyl group Then, 0.01 to 5 parts by weight of a crosslinking agent, 0.1 to 5 parts by weight of a dispersant, and 0.1 to 5 parts by weight of a thermal polymerization initiator are added. Next, while stirring with a three-one motor, the temperature is raised to a temperature higher than the reaction temperature of the thermal polymerization initiator in an oil bath, polymerization is started, and the state is maintained for 5 hours or longer to react. Thereafter, unreacted compounds are removed using a centrifuge to obtain insulating particles in which the surface of the insulating particle body is covered with the layer.

When there are hydroxyl groups on the surface of the insulating particles and the surface of the conductive particles, the adhesion between the insulating particles and the conductive particles is moderately increased by the dehydration reaction.

Examples of the compound having a hydroxyl group for introducing a hydroxyl group on the surface of the insulating particles include a P—OH group-containing compound and a Si—OH group-containing compound.

Specific examples of the P—OH group-containing compound include acid phosphooxyethyl methacrylate, acid phosphooxypropyl methacrylate, acid phosphooxypolyoxyethylene glycol monomethacrylate, and acid phosphooxypolyoxypropylene glycol monomethacrylate. Only one type of P—OH group-containing compound may be used, or two or more types may be used in combination.

Specific examples of the Si—OH group-containing compound include vinyltrihydroxysilane and 3-methacryloxypropyltrihydroxysilane. As for the said Si-OH group containing compound, only 1 type may be used and 2 or more types may be used together.

For example, insulating particles having a hydroxyl group on the surface can be obtained by a treatment using a silane coupling agent. Examples of the silane coupling agent include hydroxytrimethoxysilane.

The particle size of the insulating particles can be appropriately selected depending on the particle size of the conductive particles, the use of the conductive particles with insulating particles, and the like. The average particle diameter of the insulating particles is preferably in the range of 0.005 to 1 μm. The average particle diameter of the insulating particles is more preferably 0.01 μm or more, and more preferably 0.5 μm or less. When the average particle diameter of the insulating particles is equal to or more than the above lower limit, the conductive particles in the plurality of conductive particles with insulating particles are in contact with each other when the conductive particles with insulating particles are dispersed in the binder resin. It becomes difficult. When the average particle diameter of the insulating particles is not more than the above upper limit, it is not necessary to make the pressure too high in order to eliminate the insulating particles between the electrodes and the conductive particles when connecting the electrodes, There is no need to heat to high temperatures.

The “average particle size” of the insulating particles indicates the number average particle size. The average particle size of the insulating particles is determined using a particle size distribution measuring device or the like.

The average particle size of the insulating particles is preferably 1/3 or less of the average particle size of the conductive particles, and more preferably 1/5 or less. The average particle diameter of the insulating particles is preferably 1/1000 or more of the average particle diameter of the conductive particles, more preferably 1/100 or more, and most preferably 1/10 or more. When the average particle diameter of the insulating particles is 1/5 or less of the average particle diameter of the conductive particles, for example, when manufacturing the conductive particles with insulating particles, the insulating particles are further separated on the surface of the conductive particles. It can be attached efficiently.

The average particle diameter of the insulating particles is preferably 0.5 times or more, more preferably 1 or more times the thickness of the conductive layer in the conductive particles. The average particle size of the insulating particles is preferably 20 times or less, more preferably 10 times or less the thickness of the conductive layer in the conductive particles. When the average particle diameter of the insulating particles and the thickness of the conductive layer satisfy such a preferable relationship, the conductive particles in the plurality of conductive particles with insulating particles are difficult to contact with each other, and the conductive layer and the electrode are not in contact with each other. Insulating particles can be easily eliminated.

The average particle size of the insulating particles is preferably at least 0.5 times the average particle size of the core substance, more preferably at least 1 time. The average particle size of the insulating particles is preferably 20 times or less, more preferably 10 times or less, the average particle size of the core substance. When the average particle diameter of the insulating particles and the average particle diameter of the core substance satisfy such a preferable relationship, the conductive particles in the plurality of conductive particles with insulating particles are difficult to contact each other, and the conductive layer and Insulating particles between the electrodes can be easily eliminated.

The “average particle size” of the core material indicates the number average particle size. The average particle size of the core substance is determined using a particle size distribution measuring device or the like.

The elastic modulus of the insulating particle main body is preferably 1/1 or less, more preferably 1/2 or less, of the elastic modulus of the conductive layer in the conductive particles. The elastic modulus of the insulating particle body is preferably 1/100 or more, and more preferably 1/50 or more, of the elastic modulus of the conductive layer in the conductive particles. When the elastic modulus of the insulating particles and the elastic modulus of the conductive layer satisfy such a preferable relationship, the conductive particles in the plurality of conductive particles with insulating particles are difficult to contact each other, and the conductive layer and the electrode Insulating particles can be easily eliminated.

The above elastic modulus is measured according to JIS K7208 using a precision universal testing machine.

When the average particle diameter of the insulating particles is 200 nm, the sphericity of the insulating particles is preferably 50 nm or less.

The coefficient of variation (CV value) of the insulating particles is preferably 1% or more, preferably 10% or less, more preferably 8% or less.

Two or more kinds of insulating particles having different particle diameters may be used. In this case, since small insulating particles can exist between the large insulating particles on the surface of the conductive particles, the exposed area of the conductive particles can be reduced. Therefore, even if a plurality of conductive particles with insulating particles are in contact with each other, adjacent conductive particles are difficult to contact, and thus a short circuit between adjacent electrodes can be suppressed. The average particle size of the small insulating particles is preferably 1/2 or less of the average particle size of the large insulating particles. The number of small insulating particles is preferably ¼ or less of the number of large insulating particles.

The layer formed of the polymer compound preferably has higher flexibility than the insulating particle body. In general, a layer formed of a polymer compound formed of an organic compound has higher flexibility than inorganic particles. The flexibility between the layer and the insulating particle body can be evaluated, for example, by measuring the compression recovery rate. Further, by measuring the compression recovery rate of the insulating particles rather than the compression recovery rate of the insulating particle main body and the compression recovery rate of the layer, and calculating the difference from the value of the compression recovery rate of the insulating particles, the layer and The flexibility with the insulating particle body can be determined.
The compression recovery rate can be calculated, for example, by calculating the ratio of the amount of change in particle size when the weight is released to the amount of change in particle size when a constant load is applied to the insulating particles.

For example, insulating particles whose surfaces are coated with a layer formed of a polymer compound are compressed with a force of 1 N at 20 ° C. using a micro compression tester (manufactured by Shimadzu Corporation), and then subjected to weighting. The compression recovery rate can be measured by measuring the deformation of the particles when the is opened.

In the measurement, the insulating particles were put into a 1 cm ³ (inner diameter 1 cm × width 1 cm × height 1 cm) stainless steel cup so as to be closely packed, and then 0.90 cm ² (length 0.95 cm × width 0.3 mm). A 95 cm) stainless steel lid may be installed so as to be movable, a compression test may be performed from the top of the lid, and the compression recovery rate may be measured from the movement range of the lid.

(Conductive particles with insulating particles)
Examples of the method for attaching the insulating particles to the surfaces of the conductive particles and the conductive layer include chemical methods and physical or mechanical methods. 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 method include spray drying, hybridization, electrostatic adhesion, spraying, dipping, and vacuum deposition. However, since the hybridization method tends to cause the detachment of the insulating particles, the method of attaching the insulating particles to the surfaces of the conductive particles and the conductive layer is a method other than the hybridization method. Is preferred. Among these, a method of attaching the insulating particles to the surface of the conductive layer through a chemical bond is preferable because the insulating particles are not easily detached.

In the conductive particles with insulating particles according to the present invention, the insulating particles are preferably not attached by a hybridization method. It is preferable that the polymer compound is not attached to a portion other than the portion to which the insulating particles are attached on the surface of the conductive particles. Such conductive particles with insulating particles can be obtained without using a hybridization method.

As shown in FIG. 6, in the conventional conductive particles 101 with insulating particles using the hybridization method, the portions 102 b other than the portions 102 a on the surface of the conductive particles 102 are attached to the portions 102 b. Also, the polymer compound 104 adheres. This is because in the hybridization method, a compressive shear force is applied, the insulating particles are repeatedly attached and detached, and the insulating particles are gradually attached. The layer formed of the polymer compound of the insulating particles is peeled off by the compressive shearing force, and the peeled polymer compound is attached to a portion other than the portion where the insulating particles are attached on the surface of the conductive particles. The polymer compound adhering to the portion other than the portion to which the insulating particles adhere on the surface of the conductive particles increases the volume resistivity of the conductive particles or decreases the connection resistance between the electrodes.

As an example of a method for attaching insulating particles to the surfaces of the conductive particles and the conductive layer, the following methods may be mentioned.

First, the conductive particles are put in a solvent such as water, and the insulating particles are gradually added while stirring. After sufficiently stirring, the conductive particles with insulating particles are separated and dried by a vacuum dryer or the like to obtain conductive particles with insulating particles.

The conductive layer preferably has a reactive functional group capable of reacting with insulating particles on the surface. The insulating particles preferably have a reactive functional group capable of reacting with the conductive layer on the surface. These reactive functional groups make it difficult for the insulating particles to be unintentionally detached from the surface of the conductive particles.
As the reactive functional group, an appropriate group is selected in consideration of reactivity. Examples of the reactive functional group include a hydroxyl group, a vinyl group, and an amino group. Since the reactivity is excellent, the reactive functional group is preferably a hydroxyl group. The conductive particles preferably have a hydroxyl group on the surface. The insulating particles preferably have a hydroxyl group on the surface.

(Anisotropic conductive material)
The anisotropic conductive material according to the present invention includes the conductive particles with insulating particles of the present invention and a binder resin.

When the conductive particles with insulating particles are used, the insulating particles are not easily detached from the surface of the conductive particles when the conductive particles with insulating particles are dispersed in the binder resin.

The binder resin is not particularly limited. In general, an insulating resin is used as the binder resin. Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. As for the said binder resin, only 1 type may be used and 2 or more types may be used together.

Examples of the vinyl resin include vinyl acetate resin, acrylic resin, and styrene resin. Examples of the thermoplastic resin include polyolefin resin, ethylene-vinyl acetate copolymer, and 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 photocurable 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 a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated product of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogenated products of styrene block copolymers. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.
In addition to the conductive particles with insulating particles and the binder resin, the anisotropic conductive material includes, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, and an antioxidant. In addition, various additives such as a heat stabilizer, a light stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant may be contained.

The method for dispersing the conductive particles with insulating particles in the binder resin is not particularly limited, and a conventionally known dispersion method can be used. Examples of a method for dispersing conductive particles with insulating particles in a binder resin include, for example, a method in which conductive particles with insulating particles are added to a binder resin and then kneaded and dispersed with a planetary mixer or the like. Conductive particles with particles are uniformly dispersed in water or an organic solvent using a homogenizer or the like, then added to the binder resin, kneaded and dispersed with a planetary mixer, etc., and the binder resin is water or organic Examples include a method of adding conductive particles with insulating particles after diluting with a solvent or the like, and kneading and dispersing with a planetary mixer or the like.

The anisotropic conductive material according to the present invention can be used as an anisotropic conductive paste or an anisotropic conductive film. When the anisotropic conductive material according to the present invention is used as a film-like adhesive such as an anisotropic conductive film, the film-like adhesive including the conductive particles with insulating particles is used as the insulating particles. A film-like adhesive that does not contain attached conductive particles or conductive particles may be laminated.

The anisotropic conductive material according to the present invention is preferably an anisotropic conductive paste. An anisotropic conductive paste is excellent in handleability and circuit fillability. When obtaining an anisotropic conductive paste, a relatively large force is imparted to the conductive particles with insulating particles, but by using the conductive particles with insulating particles of the present invention, insulation from the surface of the conductive particles is achieved. It is possible to suppress the separation of the particles.

In 100% by weight of the anisotropic conductive material, the content of the binder resin is preferably in the range of 10 to 99.99% by weight. The content of the binder resin is more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, and more preferably 99.9% by weight or more. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles with insulating particles can be efficiently arranged between the electrodes, and the conduction reliability of the connection target member connected by the anisotropic conductive material Can be further increased.

In 100% by weight of the anisotropic conductive material, the content of the conductive particles with insulating particles is preferably in the range of 0.01 to 40% by weight. The content of the conductive particles with the upper insulating particles is more preferably 0.1% by weight or more, more preferably 20% by weight or less, and still more preferably 15% by weight or less. When the content of the conductive particles with insulating particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes can be further enhanced.

(Connection structure)
By connecting the connection target members using the conductive particles with insulating particles of the present invention or using an anisotropic conductive material containing the conductive particles with insulating particles and a binder resin, a connection structure Can be obtained.

The connection structure includes a first connection target member, a second connection target member, and a connection portion that electrically connects the first and second connection target members. The connection structure is preferably formed of conductive particles with insulating particles or formed of an anisotropic conductive material including the conductive particles with insulating particles and a binder resin. In the case where conductive particles with insulating particles are used, the connecting portion itself is formed of conductive particles with insulating particles. That is, the first and second connection target members are electrically connected by the conductive particles in the conductive particles with insulating particles.

FIG. 4 is a cross-sectional view schematically showing a connection structure using the conductive particles 1 with insulating particles shown in FIG.

4 includes a first connection target member 52, a second connection target member 53, and a connection portion 54 that connects the first and second

connection target members

52 and 53. Prepare. The connection part 54 is formed of an anisotropic conductive material including the conductive particles 1 with insulating particles and a binder resin. In FIG. 4, the conductive particles 1 with insulating particles are schematically shown for convenience of illustration. Instead of the conductive particles 1 with insulating particles, conductive particles 21 and 41 with insulating particles may be used.

The first connection object member 52 has a plurality of electrodes 52b on the upper surface 52a. The second connection target member 53 has a plurality of electrodes 53b on the lower surface 53a. The electrode 52b and the electrode 53b are electrically connected by one or more conductive particles 1 with insulating particles. Therefore, the first and second

connection target members

52 and 53 are electrically connected by the conductive particles 1 with insulating particles.

The manufacturing method of the connection structure is not particularly limited. As an example of a method for manufacturing a connection structure, the anisotropic conductive material is disposed between a first connection target member and a second connection target member to obtain a laminate, and then the laminate is heated and The method of pressurizing is mentioned.
The pressurizing pressure is about 9.8 × 10 ⁴ to 4.9 × 10 ⁶ Pa. The heating temperature is about 120 to 220 ° C.

When the laminate is heated and pressed, the insulating particles 3 existing between the conductive particles 2 and the

electrodes

52b and 53b can be eliminated. For example, during the heating and pressurization, the insulating particles 3 existing between the conductive particles 2 and the

electrodes

52b and 53b are melted or deformed, so that the surface of the conductive particles 2 Is partially exposed. Note that a large force is applied during the heating and pressurization, so that some of the insulating particles 3 are peeled off from the surface of the conductive particles 2 and the surface of the conductive particles 2 is partially exposed. Sometimes. The portion where the surface of the conductive particle 2 is exposed contacts the

electrodes

52b and 53b, whereby the

electrodes

52b and 53b can be electrically connected via the conductive particle 2.

Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors, and diodes, and electronic components such as circuit boards such as printed boards, flexible printed boards, and glass boards. The anisotropic conductive material is in a paste form, and is preferably applied on the connection target member in a paste state. The conductive particles with insulating particles and the anisotropic conductive material are preferably used for connection of a connection target member that is an electronic component.

The conductive particles with insulating particles according to the present invention are particularly suitable for COG having a glass substrate and a semiconductor chip as connection target members, or FOG having a glass substrate and a flexible printed circuit board (FPC) as connection target members. Is done. The conductive particles with insulating particles according to the present invention may be used for COG or FOG. In the connection structure according to the present invention, the first and second connection target members are preferably a glass substrate and a semiconductor chip, or a glass substrate and a flexible printed board. The first and second connection target members may be a glass substrate and a semiconductor chip, or may be a glass substrate and a flexible printed board.

It is preferable that bumps are provided on a semiconductor chip used in a COG having a glass substrate and a semiconductor chip as connection target members. The bump size is preferably an electrode area of 1000 μm ² or more and 10,000 μm ² or less. The electrode space in the semiconductor chip provided with the bump (electrode) is preferably 30 μm or less, more preferably 20 μm or less, and still more preferably 10 μm or less. For such COG applications, the conductive particles with insulating particles according to the present invention are preferably used. In the FPC used in the FOG using a glass substrate and a flexible printed circuit as a connection target member, the electrode space is preferably 30 μm or less, more preferably 20 μm or less.

Examples of the electrode provided on the connection target member include metal electrodes 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 object 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. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient and the electrode by which the aluminum layer was laminated | stacked on the surface of the metal oxide layer may be sufficient. Examples of the metal oxide 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 specifically described with reference to examples and comparative examples. The present invention is not limited only to the following examples.

Example 1
Conductive particles:
Conductive particles (average particle diameter: 3.01 μm, conductive layer thickness: 0.2 μm) having a nickel plating layer (conductive layer) formed on the surface of divinylbenzene resin particles were prepared.

Production of insulating particles:
The surface of silica particles (average particle size 200 nm) produced using the sol-gel method was coated with vinyltriethoxysilane, and insulating particles having vinyl groups as reactive functional groups on the surface were obtained as insulating particle bodies. . Specifically, 10 parts by weight of silica particles were dispersed in 400 ml of a liquid in which water and ethanol were mixed at a weight ratio of 1: 9 using a three-one motor to obtain a first dispersion. Next, 0.1 part by weight of vinyltriethoxysilane was dispersed in 100 ml of a mixture of water and ethanol in a weight ratio of 1: 9 to obtain a second dispersion. Thereafter, the second dispersion was dropped into the first dispersion over 10 minutes to obtain a mixed solution. After the dropwise addition, the resulting mixture was stirred for 30 minutes. Thereafter, the mixed solution was filtered, dried at 100 ° C. for 2 hours, and then sieved to obtain an insulating particle body.

In 200 mL of water, 1 part by weight of the insulating particle main body, 2 parts by weight of methacrylic acid as a polymer compound, 1 part by weight of ethylene glycol dimethacrylate as a compound as a polymer compound, and an initiator (V-50 manufactured by Wako Pure Chemical Industries, Ltd.) 0.5 parts by weight and 1 part by weight of polyoxyethylene lauryl ether (“Emulgen 106” manufactured by Kao Co., Ltd.) as an emulsifier are blended and an ultrasonic irradiation machine is used And sufficiently emulsified. Then, it heated up to 70 degreeC, fully stirring with a three-one motor, and hold | maintained at 70 degreeC for 6 hours, and the said monomer was polymerized.

Thereafter, the mixture was cooled, solid-liquid separation was performed twice with a centrifuge, excess monomers were removed by washing, and insulating particles whose entire surface was coated with the polymer compound were obtained. Next, the obtained insulating particles were dispersed in 30 mL of pure water to obtain a dispersion of insulating particles.

At this time, the average particle diameter of the insulating particles coated with the polymer compound was 324 nm.

Production of conductive particles with insulating particles:
A 1 L separable flask was charged with 250 mL of pure water, 50 mL of ethanol, and 15 parts by weight of the conductive particles, and stirred sufficiently to obtain a liquid containing conductive particles. To the liquid containing the conductive particles, the dispersion liquid of the insulating particles was dropped over 10 minutes while applying ultrasonic waves, and then heated to 40 ° C. and stirred for 1 hour. Then, it filtered and it was made to dry at 100 degreeC with a vacuum dryer for 8 hours, and the electroconductive particle with an insulating particle was obtained.

(Example 2)
When obtaining insulating particles whose entire surface is coated with a polymer compound, the compound that becomes the polymer compound was changed to 2.5 parts by weight of methacrylic acid and 1.2 parts by weight of divinylbenzene. In the same manner as in Example 1, conductive particles with insulating particles were obtained.

In addition, the average particle diameter of the insulating particles coated with the polymer compound in the state of dispersion of the insulating particles was 335 nm.

(Example 3)
The surface of the silica particles was coated with methacryloxypropyltriethoxysilane to obtain insulating particles having methacryloyl groups on the surface as the insulating particle main body, and the entire surface was made of a polymer compound using the insulating particle main body. Example 1 except that when the coated insulating particles were obtained, the compound to be a polymer compound was changed to 2.2 parts by weight of vinyl acetate and 1.0 part by weight of N, N-methylenebisacrylamide. In the same manner, conductive particles with insulating particles were obtained.

The insulating particle body was obtained in the same manner as in Example 1 except that 10 parts by weight of silica particles and 0.1 part by weight of methacryloxypropyltriethoxysilane were used when obtaining the insulating particle body. It was. The average particle diameter of the insulating particles covered with the polymer compound in the state of the dispersion of the insulating particles was 326 nm.

Example 4
Conductivity in which nickel powder (100 nm) is attached as a core material to the surface of divinylbenzene resin particles, and a nickel plating layer (conductive layer) is formed on the surface of divinylbenzene particles to which nickel powder is attached Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that particles (average particle size: 3.03 μm, conductive layer thickness: 0.21 μm) were used.

(Example 5)
When obtaining insulating particles whose entire surface is coated with the polymer compound, the compound to be the polymer compound was changed to 0.4 parts by weight of methacrylic acid and 0.05 parts by weight of ethylene glycol dimethacrylate. Except that, conductive particles with insulating particles were obtained in the same manner as Example 1.

In addition, the average particle diameter of the insulating particles coated with the polymer compound in the state of dispersion of the insulating particles was 248 nm.

(Comparative Example 1)
Conductive particles with insulating particles were obtained in the same manner as in Example 1 except that the surface of the insulating particle main body was not coated with the polymer compound.

That is, when the insulating particles are attached to the surface of the conductive particles, the insulating particles (not coated with the polymer compound) having the vinyl group on the surface are used as pure water as a dispersion of the insulating particles. A dispersion liquid dispersed in 30 mL was used.

(Example 6)
Using the physical / mechanical hybridization method, the insulating particles produced in Example 1 were attached to the conductive particles prepared in Example 1 to obtain conductive particles with insulating particles.

(Comparative Example 2)
Insulating particles are provided in the same manner as in Example 1 except that polymer fine particles (average particle size 240 nm) (not coated with a polymer compound) made of a polymer of divinylbenzene are used as the insulating particles. Conductive particles were obtained.

(Evaluation of Examples 1 to 6 and Comparative Examples 1 and 2)
(1) Coverage rate of conductive particles with insulating particles and residual rate of insulating particles Before sonication, 100 conductive particles with insulating particles of Examples and Comparative Examples were observed by observation with an SEM. . The coverage X1 which is the projected area of the portion covered with the insulating particles in the entire surface area of the conductive particles in the conductive particles with the insulating particles was determined.

Next, 3 parts by weight of conductive particles with insulating particles was added to 100 parts by weight of ethanol to obtain a conductive particle-containing liquid with insulating particles. This conductive particle-containing liquid with insulating particles was subjected to ultrasonic treatment while being stirred for 5 minutes at 20 ° C. and 38 kHz with a 400 W ultrasonic cleaner. After the ultrasonic treatment, 100 conductive particles with insulating particles are observed by observation with an SEM, and the portion of the conductive particles with insulating particles covered by the insulating particles occupying the entire surface area of the conductive particles. The coverage X2, which is the projected area, was determined. The remaining rate of the insulating particles at 38 kHz was obtained from the following formula (1) from the coverage X1 and the coverage X2.

Further, the residual rate of the insulating particles at 40 kHz was obtained in the same manner except that the sonication conditions were changed from 38 kHz to 40 kHz.

(2) Fabrication of connection structure 1 (COG1)
The conductive particles with insulating particles of Examples and Comparative Examples were added to “Struct Bond XN-5A” manufactured by Mitsui Chemicals so as to have a content of 10% by weight, and dispersed to obtain an anisotropic conductive paste. It was.

A transparent glass substrate having an ITO electrode pattern having an L / S of 20 μm / 20 μm on the upper surface was prepared. Moreover, the semiconductor chip which has a copper electrode pattern which L / S is 20 micrometers / 20 micrometers on the lower surface was prepared. The electrode area of the bump of this semiconductor chip was 2000 μm ² .

The obtained anisotropic conductive paste was applied on the transparent glass substrate so as to have a thickness of 30 μm to form an anisotropic conductive paste layer. Next, the semiconductor chip was stacked on the anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 3 MPa is applied to form the anisotropic conductive paste layer. Completely cured at 185 ° C. to obtain a connection structure (COG1).

(3) Conductivity evaluation (between upper and lower electrodes)
The connection resistance between the upper and lower electrodes of the obtained connection structure (COG1) was measured by a four-terminal method. The average value of the two connection resistances was calculated. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance. The case where the average value of the connection resistance was 2.0Ω or less was judged as “◯”, and the case where the average value of the connection resistance exceeded 2.0Ω was judged as “X”.

(4) Insulation evaluation (between adjacent electrodes in the horizontal direction)
In the obtained connection structure (COG1), the presence or absence of leakage between adjacent electrodes was evaluated by measuring the resistance with a tester. When the resistance exceeded 500 MΩ, the result was judged as “O” as no leakage, and when the resistance was 500 MΩ or less, the result was judged as “x” as a leakage.

(5) Fabrication of connection structure 2 (COG2)
A transparent glass substrate having an ITO electrode pattern having an L / S of 30 μm / 30 μm on the upper surface was prepared. Moreover, the semiconductor chip which has a copper electrode pattern whose L / S is 30 micrometers / 30 micrometers on the lower surface was prepared. The electrode area of the bump of this semiconductor chip was 3000 μm ² . A connection structure (COG2) was obtained in the same manner as in the production of the connection structure (2) except that the connection target members were changed.

(6) Conductivity evaluation (between upper and lower electrodes)
About the obtained connection structure (COG2), evaluation similar to said (3) was performed.

(7) Insulation evaluation (between adjacent electrodes in the horizontal direction)
About the obtained connection structure (COG2), evaluation similar to said (4) was performed.

(8) Fabrication of connection structure 3 (FOG)
The conductive particles with insulating particles of Examples and Comparative Examples were added to “Struct Bond XN-5A” manufactured by Mitsui Chemicals so that the content was 5% by weight, and dispersed to obtain an anisotropic conductive paste. It was.

A transparent glass substrate having an ITO electrode pattern with an L / S of 30 μm / 30 μm on the upper surface was prepared. Moreover, the flexible printed circuit board which has a copper electrode pattern which L / S is 30 micrometers / 30 micrometers on the lower surface was prepared.

The obtained anisotropic conductive paste was applied on the transparent glass substrate so as to have a thickness of 50 μm to form an anisotropic conductive paste layer. Next, the flexible printed circuit board was laminated on the anisotropic conductive paste layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 1 MPa is applied to form the anisotropic conductive paste layer. Completely cured at 185 ° C. to obtain a connection structure.

(9) Conductivity evaluation (between upper and lower electrodes)
About the obtained connection structure (FOG), evaluation similar to said (3) was performed.

(10) Insulation evaluation (between adjacent electrodes in the horizontal direction)
About the obtained connection structure (FOG), evaluation similar to said (4) was performed.
The results are shown in Table 1 below.

In addition, in the insulating particles obtained in Examples 1 to 6, the layer formed of the polymer compound is more flexible than the silica particles by measuring the compression recovery rate of the insulating particles by the method described above. Confirmed that it was high.

Further, in the conductive particles with insulating particles of Examples 1 to 5, it was confirmed that the polymer compound was not attached to the portion other than the portion to which the insulating particles were attached on the surface of the conductive particles. . In Example 6, since the physical / mechanical hybridization method is used, the portion where the polymer compound is attached to the portion other than the portion where the insulating particles are attached on the surface of the conductive particles. was there. Thus, if the polymer compound is attached to a portion other than the portion to which the insulating particles are attached on the surface of the conductive particles, the conduction reliability may be lowered depending on the case.

(Example 7)
Conductive particles:
Conductive particles (average particle diameter: 3.01 μm, conductive layer thickness: 0.2 μm) having a nickel plating layer (conductive layer) formed on the surface of divinylbenzene resin particles were prepared.

Production of insulating particles:
The surface of silica particles (average particle size 200 nm) produced using the sol-gel method was coated with vinyltriethoxysilane, and insulating particles having vinyl groups as reactive functional groups on the surface were obtained as insulating particle bodies. .

In 200 mL of water, 1 part by weight of the insulating particle main body, 0.22 parts by weight of methacrylic acid as a polymer compound, and 0.05 part by weight of ethylene glycol dimethacrylate as a compound as a polymer compound And 0.5 parts by weight of an initiator (“V-50” manufactured by Wako Pure Chemical Industries, Ltd.) were heated to 70 ° C. with sufficient stirring with a three-one motor, held at 70 ° C. for 6 hours, Was polymerized.

(Example 8)
When obtaining insulating particles whose entire surface is coated with a polymer compound, the compound that becomes the polymer compound was changed to 0.33 parts by weight of methacrylic acid and 0.05 parts by weight of divinylbenzene. In the same manner as in Example 7, conductive particles with insulating particles were obtained.

Example 9
The surface of the silica particles was coated with methacryloxypropyltriethoxysilane to obtain insulating particles having methacryloyl groups on the surface as the insulating particle main body, and the entire surface was made of a polymer compound using the insulating particle main body. Example 7 except that when the coated insulating particles were obtained, the polymer compound was changed to 0.28 parts by weight of vinyl acetate and 0.05 parts by weight of N, N-methylenebisacrylamide. In the same manner, conductive particles with insulating particles were obtained.

(Example 10)
Conductivity in which nickel powder (100 nm) is attached as a core material to the surface of divinylbenzene resin particles, and a nickel plating layer (conductive layer) is formed on the surface of divinylbenzene particles to which nickel powder is attached Conductive particles with insulating particles were obtained in the same manner as in Example 7, except that particles (average particle size: 3.03 μm, conductive layer thickness: 0.21 μm) were used.

(Example 11)
Using the physical / mechanical hybridization method, the insulating particles produced in Example 7 were attached to the conductive particles prepared in Example 7 to obtain conductive particles with insulating particles.

(Evaluation of Examples 7 to 11)
The conductive particles with insulating particles obtained in Examples 7 to 11 were evaluated in the same manner as in Examples 1 to 6 and Comparative Examples 1 and 2.

The results are shown in Table 2 below.

In addition, in the insulating particles obtained in Examples 7 to 10, the layer formed of the polymer compound is more flexible than the silica particles by measuring the compression recovery rate of the insulating particles by the method described above. Confirmed that it was high.

Further, in the conductive particles with insulating particles of Examples 7 to 10, it was confirmed that the polymer compound was not attached to the portion other than the portion to which the insulating particles were attached on the surface of the conductive particles. . In Example 11, since the physical / mechanical hybridization method is used, the portion where the polymer compound is attached to the portion other than the portion where the insulating particles are attached on the surface of the conductive particles. was there. Thus, if the polymer compound is attached to a portion other than the portion to which the insulating particles are attached on the surface of the conductive particles, the conduction reliability may be lowered depending on the case.

(Example 12)
In the same manner as in Example 1 except that polymer fine particles (average particle diameter 200 nm) having a hydroxy group on the surface, prepared by polymerizing methacrylic acid and ethylene glycol dimethacrylate instead of silica particles, were used. Conductive particles with insulating particles were obtained.

(Evaluation of Example 12)
The conductive particles with insulating particles obtained in Example 12 were evaluated in the same manner as in Examples 1 to 6 and Comparative Examples 1 and 2.

The results are shown in Table 3 below.

In the insulating particles obtained in Example 12, the shell layer formed of the polymer compound is more flexible than the core particles formed of the polymer by measuring the compression recovery rate of the insulating particles. Was confirmed to be high.

Further, in the conductive particles with insulating particles of Example 12, it was confirmed that the polymer compound was not attached to the portion other than the portion to which the insulating particles were attached on the surface of the conductive particles.

The Cv values of the conductive particles with insulating particles obtained in Examples 1 to 11 and Comparative Examples 1 and 2 are 4.6, the 10% K value at 20 ° C. is 4650 N / mm ² , and the compression at 20 ° C. The recovery rate was 51%.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle with insulating particle 2 ... Conductive particle 3 ... Insulating particle 5 ... Insulating particle main body 6 ... Layer 11 ... Base particle 12 ... Conductive layer 21 ... Conductive particle with insulating particle 22 ... Conductive Particle 31 ... Conductive layer 32 ... Core material 33 ... Protrusion 41 ... Conductive particle with insulating particles 42 ... Conductive particle 46 ... Conductive layer 46a ... First conductive layer 46b ... Second conductive layer 47 ... Core material 48 ... Projection 51 ... Connection structure 52 ... First connection object member 52a ... Upper surface 52b ... Electrode 53 ... Second connection object member 53a ... Lower surface 53b ... Electrode 54 ... Connection part

Claims

Conductive particles having at least a conductive layer on the surface;
Insulating particles attached to the surface of the conductive particles,
The insulating particles have an insulating particle body, and a layer that covers at least a part of the surface of the insulating particle body and is formed of a polymer compound,
Conductive particles with insulating particles, wherein the insulating particle main body and the layer are chemically bonded.
The conductive particles with insulating particles according to claim 1, wherein the insulating particle body is inorganic particles.
The conductive particles with insulating particles according to claim 1, wherein the layer has higher flexibility than the insulating particle main body.
Using the insulating particle main body having a reactive functional group on the surface and a polymer compound or a compound to be the polymer compound, the reactive functional group on the surface of the insulating particle main body is The insulating particles in which the insulating particle main body and the layer are chemically bonded are obtained by chemically bonding the formed layers. Conductive particles with insulating particles according to 1.
The insulation according to any one of claims 1 to 4, wherein the insulating particles are not formed by friction by mixing using the insulating particle main body and a polymer compound or a compound to be the polymer compound. Conductive particles with conductive particles.
When the conductive particle-containing liquid with insulating particles obtained by adding 3 parts by weight of conductive particles with insulating particles to 100 parts by weight of ethanol was subjected to ultrasonic treatment for 5 minutes at 20 ° C. and 40 kHz, the following formula (1) The conductive particles with insulating particles according to any one of claims 1 to 5, wherein the residual ratio of the insulating particles obtained by the above is 60 to 95%.
Residual ratio of insulating particles (%) = (coverage ratio after sonication / coverage ratio before sonication) × 100 (1)
When the conductive particle-containing liquid with insulating particles obtained by adding 3 parts by weight of conductive particles with insulating particles to 100 parts by weight of ethanol was subjected to ultrasonic treatment for 5 minutes at 20 ° C. and 38 kHz, the following formula (1) The conductive particles with insulating particles according to any one of claims 1 to 6, wherein the residual ratio of the insulating particles obtained by the method is 60 to 95%.
Residual ratio of insulating particles (%) = (coverage ratio after sonication / coverage ratio before sonication) × 100 (1)
The conductive material with insulating particles according to any one of claims 1 to 7, wherein a covering ratio that is an area of a portion covered with the insulating particles occupying the entire surface area of the conductive particles is 40% or more. Sex particles.
The conductive particles with insulating particles according to claim 8, wherein the coverage ratio exceeds 50%.
An anisotropic conductive material comprising the conductive particles with insulating particles according to any one of claims 1 to 9, and a binder resin.
The anisotropic conductive material according to claim 10, which is an anisotropic conductive paste.
A first connection target member, a second connection target member, and a connection part connecting the first and second connection target members;
The connecting portion is formed of the conductive particles with insulating particles according to any one of claims 1 to 9, or an anisotropic conductive material including the conductive particles with insulating particles and a binder resin. A connection structure made of a material.