TW201401299A - Conductive particles, anisotropic conductive adhesive film and connection structure - Google Patents

Abstract

The invention relates to a conductive particle, which has a base particle and an insulation product particle coated on the surface of the base particle. The base particle has a plastic core body and a plating layer containing at least an alloy layer of Ni/P coated on the surface of the plastic core body. The particle diameter of the base particle is between 2.0 μ m (equal to or greater than) and 3.0 μ m (equal to or less than). The saturation magnetization of the base particle is equal to or less than 45 emu/cm<SP>3</SP>. The particle diameter of the insulation product particle is between 180 nm (equal to or greater than) and 500 nm (equal to or less than).

Description

Conductive particles, anisotropic conductive adhesive film and connection structure

The present invention relates to a conductive particle, an anisotropic conductive adhesive film, and a bonded structure.

Previously, when the circuit members were electrically connected to each other or an integrated circuit (IC) wafer or an electronic component and a circuit member, an adhesive or an anisotropic conductive adhesive in which conductive particles were dispersed were used. This type of connection has progressed significantly in the field of liquid crystals. The method of packaging a liquid crystal driving IC on a glass panel for liquid crystal display can be roughly classified into a chip-on-glass (COG) package and a chip-on-flex (COF) package. In the COG package, a liquid crystal IC is directly bonded to a glass panel using an anisotropic conductive adhesive containing conductive particles. On the other hand, in a COF package, a liquid crystal driving IC is bonded to a flexible tape having a metal wiring, and these are bonded to a glass panel using an anisotropic conductive adhesive containing conductive particles. Here, the anisotropic conduction means that the circuit electrodes in the pressurization direction are electrically connected to each other, and the circuit electrodes in the non-pressurization direction are electrically insulated from each other. For the conductive particles, nickel plating, nickel plating, gold plating, nickel plating, and palladium plating are applied to the outside of the plastic particles. In recent years, in order to improve the guide It also has conductive particles with protrusions on the nickel-plated surface. As a method of forming a protrusion, a method of using nickel particles as a core material and performing nickel plating thereon is disclosed as disclosed in Japanese Laid-Open Patent Publication No. 2007-324138. In addition, as disclosed in Japanese Laid-Open Patent Publication No. 2000-243132, a method of forming a roughened shape on the surface of a particle by abnormal precipitation of plating is known.

With the recent refinement of the liquid crystal display, the gold bumps of the circuit electrodes of the liquid crystal driving IC are continuously narrowed and narrowed. Therefore, there is a problem that the conductive particles having the anisotropic conductive adhesive flow out to the adjacent circuit electrodes to cause a short circuit, which is particularly noticeable in the COG package. On the other hand, if the conductive particles flow out between adjacent circuit electrodes, there is a problem in that the number of conductive particles in the anisotropic conductive adhesive trapped between the gold bump and the glass panel is reduced, and between the opposing circuit electrodes The connection resistance rises, causing poor connection, and the like. In particular, in recent years, with the narrow pitch and the narrowing of the gold bumps, 20,000/mm ² or more of conductive particles are introduced per unit area, and thus the above tendency is remarkable.

Therefore, regarding the method for solving such problems, there is a method of forming an insulating adhesive on at least one surface of an anisotropic conductive adhesive, thereby preventing a method of lowering bonding quality in a COG package or a COF package (Japan) Japanese Laid-Open Patent Publication No. Hei 8-279371; and a method of coating the entire surface of a conductive particle with an insulating film (Japanese Patent No. 2794009).

However, in the method of forming an insulating adhesive on one surface of the anisotropic conductive adhesive, when the bump area is less than 3000 μm ² , the conductive particles are sometimes added in order to obtain a stable connection resistance. There is still room for improvement in insulation between adjacent circuit electrodes. Further, the circuit member obtained by coating the entire surface of the conductive particles with an insulating film has high insulation between the circuit electrodes in the non-pressurized direction, but has electrical conductivity between the circuit electrodes in the pressurizing direction. Sex is easy to reduce and other issues.

Further, when the bump area is small, there is a problem in that although the conductive particles in the anisotropic conductive adhesive are added, it is difficult for the conductive particles to remain on the bumps due to the flow of the resin at the time of pressure bonding. Due to such a problem, in terms of conduction and insulation, it is important to suppress the movement of the conductive particles when the anisotropic conductive adhesive is crimped.

The circuit member using the conductive particles obtained by coating the insulating daughter particles on the surface of the mother particles has a good balance between initial insulation properties and conductivity. However, it has been found that the insulating sub-particles have poor compatibility with metal particles such as nickel having magnetic properties, and when the particle diameter of the mother particles is less than 3 μm, magnetic aggregation of the mother particles tends to be promoted rapidly. In addition, in recent years, in order to cope with the narrow pitch of the gold bumps, there is a tendency that the diameter of the conductive particles is reduced and the diameter of the insulating sub-particles is increased. With these tendency, it is difficult for the insulating sub-particles to be adsorbed. The problem of the surface of the mother particle.

In view of the above, an object of the present invention is to provide an electrically conductive particle and an anisotropic conductive adhesive film and a connection structure obtained by using the conductive particle, and the conductive particle is used even when a mother particle having a small particle diameter is used. It can also have both insulation and continuity.

The present invention provides a conductive particle comprising a mother particle and an insulating subparticle covering a surface of the mother particle. The mother particle has a plastic core body and a plating layer covering the surface of the plastic core body and containing at least a nickel/phosphorus alloy layer. The particle size of the mother particles is 2.0 μm or more and 3.0 μm or less, the saturation magnetization of the mother particles is 45 emu/cm ³ or less, and the particle diameter of the insulating sub-particles is 180 nm or more and 500 nm or less.

The circuit member using such a conductive particle has excellent insulating properties and electrical conductivity even when a mother particle having a small particle diameter is used.

The mother particles may have protrusions on the surface, and the height of the protrusions may be smaller than the particle diameter of the insulating sub-particles.

The protrusion may be formed by coating the surface of the plastic core body to which the core material adheres with the plating layer, and the core material may be a non-magnetic body.

Since the core material is a non-magnetic material, magnetic aggregation of the mother particles can be reduced, and the insulating sub-particles can be more uniformly coated on the mother particles.

The phosphorus content of the nickel/phosphorus alloy layer may be 1.0% by mass or more and 10.0% by mass or less.

By using such conductive particles, the circuit member has more excellent conductivity, and the aggregation of the mother particles can be suppressed, and the coating unevenness (Coefficient of Variation (CV)) of the insulating particles on the surface of the mother particles can be reduced. .

The coverage of the insulating sub-particles may be in the range of 20% to 50%, and the coating unevenness (C.V.) may be 0.3 or less.

The insulating subparticles may have a layer containing a polymer or oligomer having a weight average molecular weight of 1,000 or more.

When the insulating sub-particles are coated with the polymer or the oligomer, the dispersibility of the mother particles in the dispersion medium can be improved when the mother particles are coated with the insulating sub-particles.

The above mother particles may further have a layer containing a polymer or oligomer having a weight average molecular weight of 1,000 or more. Further, the insulating sub-particles may have a particle diameter of 200 nm or more and 400 nm or less.

Further, the present invention provides an anisotropic conductive adhesive film obtained by dispersing the above-mentioned conductive particles in an adhesive.

Moreover, the present invention provides a connection structure for a circuit member, comprising: a first circuit member having a first circuit electrode formed on a main surface of the first circuit substrate; and a second surface formed on a main surface of the second circuit substrate a second circuit member of the circuit electrode; and a state between the main surface of the first circuit board and the main surface of the second circuit board, and the first circuit electrode and the second circuit electrode are disposed to face each other a circuit connecting member that connects the first circuit member and the second circuit member to each other; and the circuit connecting member includes a cured product of the anisotropic conductive adhesive film, and the first circuit electrode and the second circuit electrode that face each other are via Flat conductive particles are electrically connected.

According to the present invention, even when the mother particles having a small particle diameter are used, the insulating particles can be uniformly coated on the mother particles, and conductive particles excellent in insulating properties and conductivity can be provided, and the conductive particles can be used. An anisotropic conductive adhesive film and a connection structure.

1‧‧‧Insulators

2‧‧‧ mother particles

3‧‧‧Insulation coating

11‧‧‧Polymers or oligomers

21‧‧‧Plastic core

22‧‧‧ plating layer

23‧‧‧ core material

23a‧‧‧ Protrusion

24‧‧‧ polymer electrolyte membrane

30‧‧‧Electrical particles

31‧‧‧Adhesive

32‧‧‧layers containing conductive particles

32a‧‧‧ Hardened material of layer 32 containing conductive particles

33, 34‧‧‧layers without conductive particles

33a‧‧‧ Hardened material of layer 33 containing no conductive particles

34a‧‧‧ Hardened material of layer 34 containing no conductive particles

35‧‧‧Inorganic oxide particles

40‧‧‧ Anisotropic conductive adhesive

40a‧‧‧Circuit connection components

41‧‧‧First circuit substrate (IC chip) / first circuit electrode

42‧‧‧First circuit electrode (metal bump)

43‧‧‧Second circuit substrate (glass substrate) / second circuit electrode

44‧‧‧Second circuit electrode (ITO or IZO electrode)

50‧‧‧Connection structure

H‧‧‧ Height

Fig. 1 is a schematic cross-sectional view showing conductive particles according to an embodiment of the present invention.

2(a) is a schematic cross-sectional view showing an anisotropic conductive adhesive containing conductive particles according to an embodiment of the present invention, and FIG. 2(b) is an enlarged cross-sectional view showing a layer containing conductive particles, and the conductive particle-containing layer. The conductive particles according to an embodiment of the present invention shown in Fig. 2 (a).

3(a) and 3(b) are schematic cross-sectional views for explaining a method of manufacturing a bonded structure using an anisotropic conductive adhesive.

Hereinafter, the preferred embodiment will be described with reference to the drawings. In the description of the drawings, the same components are denoted by the same reference numerals, and the description thereof will not be repeated. In addition, in the drawings, a part of the drawing is exaggerated for easy understanding, and the ratio of the size ratio to the description does not necessarily coincide.

(conductive particles)

Fig. 1 is a schematic cross-sectional view showing conductive particles of the present embodiment. The conductive particles 30 of the present embodiment include the mother particles 2 and the insulating sub-particles 1 covering the surface of the mother particles 2.

(parent particle)

In FIG. 1, the mother particle 2 includes a plastic core body 21 and a plating layer 22 covering the surface of the plastic core body 21 and containing at least a nickel/phosphorus alloy layer. The particle diameter of the mother particles 2 may be smaller than the minimum interval of the circuit electrodes adjacent in the non-pressurization direction, and when the height of the circuit electrodes is uneven, the particle diameter of the mother particles 2 may be larger than the above-described height unevenness. In this regard, the particle diameter of the mother particle 2 is specifically 2.0 or more and 3.0 μm or less, and may be 2.2 μm or more and 3.0 μm or less, or 2.4 μm or more and 3.0 μm or less, or 2.5 μm. Above, 3.0 μm or less. When the particle diameter of the mother particle 2 is 2.0 μm or more, the height of the absorbable circuit electrode is not uniform, and the conduction reliability is not impaired. In addition, when the particle diameter of the mother particle 2 is 3.0 μm or less, the insulation reliability tends not to be impaired.

In addition, the particle diameter of the mother particle 2 means the total value of the plastic core body 21 and the plating layer 22, and does not include the insulating particle particle 1 or the protrusion 23a. The particle size of the mother particle 2 is measured by a scanning electron microscope (SEM) at a magnification of several thousand to several tens of thousands of times, and the particle diameter is measured by image analysis. The particle diameter of the mother particle 2 is derived based on the average value thereof. Hitachi (HITACHI) S-4800 (manufactured by Hitachi Hi-Tech Co., Ltd.) was used to measure the particle size of the mother particles 2.

The mother particles 2 have a saturation magnetization of 45 emu/cm ³ (4.5 × 10 ⁴ A/m) or less. The saturation magnetization of the mother particles 2 may be 30 emu/cm ³ or less, may be 10 emu/cm ³ or less, or may be 5 emu/cm ³ or less. When the saturation magnetization of the mother particles having a particle diameter of 3 μm or less is 45 emu/cm ³ or less, there is a tendency that magnetic aggregation of the mother particles is less likely to occur, whereby the insulating sub-particles are easily and uniformly coated on the surface of the mother particles. . The lower the saturation magnetization of the mother particles, the less likely it is to cause magnetic coagulation. The lower limit of the saturation magnetization of the mother particles 2 is not particularly limited. For example, the saturation magnetization of the mother particles 2 may be 0.5 emu/cm ³ (5.0×10 ² A/m) or more.

(plastic core)

The plastic core body 21 of the present embodiment is not particularly limited, and includes an acrylic resin such as polymethyl methacrylate or polymethyl acrylate or a polyolefin resin such as polyethylene, polypropylene, polyisobutylene or polybutadiene. The plastic core 21 may have a particle diameter of 2.0 μm to 2.9 μm.

(plating layer)

The conductor contained in the plating layer is not particularly limited, and examples thereof include metals such as gold, silver, copper, platinum, zinc, iron, palladium, nickel, tin, chromium, titanium, aluminum, cobalt, ruthenium, and cadmium, and indium oxide. Metal compounds such as tin (Indium Tin Oxide, ITO) and solder. Among these, the metal coated by plating may be nickel, palladium or gold from the viewpoint of corrosion resistance.

The plating layer 22 may have a single layer structure or a laminate structure (multilayer structure) including a plurality of layers. In the case where the plating layer 22 has a single layer structure, the plating layer 22 is a nickel/phosphorus alloy layer from the viewpoint of cost, conductivity, and corrosion resistance. In the case where the plating layer 22 has a multilayer structure, the plating layer 22 has a nickel/phosphorus alloy layer and one or more layers different from the nickel/phosphorus alloy layer. For example, the plating layer 22 may have a nickel/phosphorus alloy layer and other layers of precious metals such as gold and palladium located outside the nickel/phosphorus alloy layer. In the present embodiment, the nickel/phosphorus alloy layer means an alloy layer containing nickel and phosphorus.

Regarding the control of magnetic properties, the nickel/phosphorus alloy layer may also contain a metal different from nickel. By causing the nickel/phosphorus alloy layer to contain several mass% of different metals, for example, a metal having a small ion migration such as palladium, conduction deterioration can be suppressed.

The mother particles 2 may also have a functional group on the surface. Mother particle 2 has on the surface The functional group is used to adsorb the insulating sub-particles 1 to be described later on the mother particles 2. From the viewpoint of forming a bond with a functional group such as a hydroxyl group of the insulating subparticle 1 on the surface, for example, a hydroxyl group or a functional group-containing anthrone oligomer, the functional group may, for example, be a hydroxyl group, a carboxyl group or an alkoxy group. Alkoxycarbonyl group and the like. Examples of the bond of the functional group of the mother particle 2 and the insulating subparticle 1 on the surface include a covalent bond and a hydrogen bond obtained by dehydration condensation.

In the case where the mother particle 2 has a gold or palladium layer on the surface, it is preferred to use a compound having a sulfhydryl group, a sulfide group, and a disulfide group which form a coordinate bond with gold or palladium, in the mother particle. A functional group such as a hydroxyl group, a carboxyl group, an alkoxy group or an alkoxycarbonyl group is formed on the surface of 2. Examples of the above compound include mercaptoacetic acid, 2-mercaptoethanol, methyl thioglycolate, mercapto succinic acid, thioglycerin, and cysteine.

In the case where the mother particle 2 has a nickel/phosphorus alloy layer on the surface, it is preferred to form a hydroxyl group or a carboxyl group on the surface of the mother particle 2 by using a compound or a nitrogen compound having a stanol group or a hydroxyl group which forms a strong bond with nickel. a functional group such as an alkoxy group and an alkoxycarbonyl group. Examples of the above compound include carboxybenzotriazole and the like.

The method of treating the surface of the mother particle 2 with the above compound is not particularly limited, and examples thereof include dispersing the above compound such as thioglycolic acid or carboxybenzotriazole at a concentration of about 10 mmol/L to 100 mmol/L. A method of dispersing the mother particles 2 in a dispersion in an organic dispersion medium such as methanol or ethanol.

The method of forming the plating layer 22 may be, in addition to electroless plating, a method such as displacement plating or plating, which is simple, cost-effective, and controls the thickness of the plating layer 22. From the viewpoint, it may be electroless plating.

The thickness of the plating layer 22 is not particularly limited, and may be in the range of 0.001 μm to 1.0 μm, or may be in the range of 0.005 μm to 0.3 μm. When the thickness of the plating layer 22 is 0.001 μm or more, the conduction failure tends to be suppressed. When the thickness of the plating layer 22 is 1.0 μm or less, the cost tends to be high.

In consideration of the flattening of the glass electrode in recent years, the mother particle 2 may have the protrusion 23a on the surface. When the mother particles 2 are provided with the protrusions 23a on the surface, the conductivity between the circuit electrodes in the pressurizing direction tends to be improved. The method of forming the protrusion 23a on the surface of the mother particle 2 is a method of using a core material in order to uniformly form the shape of the protrusion 23a by a method of abnormal precipitation by plating and a method of using a core material. The height H of the protrusions may range from 30 nm to 300 nm, and may also range from 50 nm to 200 nm. When the height of the protrusions 23a is 300 nm or less, the short circuit between the circuit electrodes in the non-pressurization direction is suppressed. When the height of the protrusions 23a is 30 nm or more, there is a tendency that the mother particles 2 are sufficiently provided with the protrusions 23a on the surface. The effect. The mother particles 2 may cover 5 area% to 60 area% of the surface area by the protrusions, that is, the protrusion coverage of the mother particles 2 may be 5 area% to 60 area%. By setting the protrusion coverage of the mother particles 2 to the above range, the saturation magnetization of the mother particles can also be controlled.

In the case where the method of using the core material 23 is employed as a method of forming the protrusions 23a on the surface of the mother particle 2, the core material 23 is fixed to the plastic core body 21 by a chemical bond. Further, the shape of the core material 23 fixed to the plastic core body 21 is reflected to form a projection 23a on the surface of the mother particle 2. The core material 23 can be exemplified by a strong magnetic material such as nickel. Materials, and non-magnetic materials such as cerium oxide, cross-linked resin, gold and palladium. The core material 23 can be made of a non-magnetic material because the saturation magnetization of the mother particles 2 is lowered, and the magnetic aggregation of the mother particles 2 tends to decrease when the insulating particles are coated. Further, even if the core material 23 is a ferromagnetic material (for example, nickel), the saturation magnetization of the mother particles 2 can be reduced by including the non-magnetic material (for example, phosphorus) in addition to the ferromagnetic material. The nickel/phosphorus alloy layer of the plating layer 22 may contain 1.0% by mass or more and 10.0% by mass or less of phosphorus. Here, when the core material 23 is nickel, the above ratio (phosphorus content) of phosphorus contained in the nickel/phosphorus alloy layer is expressed by the following formula: (ratio of phosphorus contained in the nickel/phosphorus alloy layer) = (total mass of phosphorus) / (total mass of phosphorus + total mass of nickel)

The "total mass of phosphorus" and the "total mass of nickel" include the mass of atoms derived from the core material 23 in addition to the nickel/phosphorus alloy layer.

When the ratio of phosphorus in the nickel/phosphorus alloy layer is 10.0% by mass or less, the plating layer 22 is excellent in conductivity and the on-resistance at the time of packaging tends to be low. When the ratio of the phosphorus is 1.0% by mass or more, the saturation magnetization of the mother particles 2 can be reduced, so that the magnetic aggregation of the mother particles 2 can be reduced, and the unevenness of the coating of the insulating particles 1 tends to be lowered. When the particle diameter of the mother particle 2 is 3 μm or less, the above tendency is remarkable.

Further, the plastic core body 21 may have a functional group selected from a hydroxyl group, a carboxyl group, an alkoxy group, a glycidyl group, and an alkoxycarbonyl group on the surface. The core material 23 can be fixed to the plastic core body 21 by the plastic core body 21 having the above functional group on the surface. example For example, by using acrylic acid as a copolymerization monomer in the production of the plastic core body 21, a plastic core body 21 having a carboxyl group on the surface can be synthesized. Further, by using glycidyl methacrylate as a copolymerization monomer, a plastic core body 21 having a glycidyl group on the surface can be synthesized.

Further, the mother particles 2 may further include a polymer electrolyte layer provided between the plastic core body 21 and the core material 23. In this case, the core material 23 is adsorbed to the plastic core body 21 by a chemical bond through the polymer electrolyte layer. For example, the plastic core body 21, the polymer electrolyte layer (not shown), and the core material 23 may each have a functional group, and the functional group of the polymer electrolyte layer forms a chemical bond with each of the functional groups of the plastic core body 21 and the core material 23. Chemical bonds include covalent bonds, hydrogen bonds, and ionic bonds.

When the pH is in the neutral range, the surface potential (kinetic potential, zeta potential) of a particle having a functional group selected from a hydroxyl group, a carboxyl group, an alkoxy group, a glycidyl group, and an alkoxycarbonyl group on the surface is usually negative. Further, when the surface potential of the core material 23 is negative, in many cases, it is difficult to sufficiently cover the surface of the particles having a negative surface potential by particles having a negative surface potential, and the polymer electrolyte layer is provided between the surfaces. The core material 23 can be effectively adsorbed to the plastic core body.

As the polymer electrolyte forming the polymer electrolyte layer, a polymer having a functional group which is ionized in an aqueous solution and having a charge in a main chain or a side chain can be used, and a polycation can also be used. Polycations can generally be used with functional groups such as polyamines, such as polyethyleneimine (PEI), polyallylamine hydrochloride (PAH), polychlorinated diallyl Alkyl ammonium (PDDA), polyvinyl pyridine (PVP), polylysine, polypropylene decylamine, and at least one or more copolymers containing these compounds. Among the polymer electrolytes, polyethyleneimine has a high charge density and a strong bonding force.

In order to avoid electron migration or corrosion, the polymer electrolyte layer may be substantially free of the following substances: alkali metal (Li, Na, K, Rb, and Cs) ions, alkaline earth metal (Ca, Sr, Ba, and Ra) ions. And halide ions (fluoride, chloride, bromide and iodide).

The polymer electrolyte is water-soluble and soluble in a mixed liquid of water and an organic solvent. The weight average molecular weight of the polymer electrolyte varies depending on the type of the polymer electrolyte to be used, and may not be uniform, but it is usually about 500 to 200,000.

By adjusting the type or molecular weight of the polymer electrolyte, the coverage of the core material 23 to the plastic core body 21 can be controlled. Specifically, when a polymer electrolyte having a high charge density such as polyethyleneimine is used, the coverage of the core material 23 tends to be high, and the charge density such as polychlorinated diallyldimethylammonium is used. In the case of a low polymer electrolyte, the coverage of the core material 23 tends to be low. In addition, when the molecular weight of the polymer electrolyte is large, the coverage of the core material 23 tends to be high, and when the molecular weight of the polymer electrolyte is small, the coverage of the core material 23 tends to be low.

The plastic core body 21 having a functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an alkoxy group, a glycidyl group and an alkoxycarbonyl group is dispersed in the polymer electrolyte solution to adsorb high on the surface of the plastic core body. A molecular electrolyte forms a polymer electrolyte layer. By providing the polymer electrolyte layer, the core material 23 is mainly adsorbed by electrostatic attraction. If the adsorption proceeds and the charge is neutralized, no further adsorption occurs. Therefore, substantially, if a certain saturation point is reached, the film thickness does not increase further.

The plastic core body 21 formed with the polymer electrolyte layer may also be self-polymerized After the electrolyte solution is taken out, the excess polymer electrolyte is removed by rinsing. The rinsing is carried out, for example, using water, alcohol or acetone. A resistivity value of 18 MΩ can also be used. Ion exchange water above cm (so-called ultrapure water). Since the polymer electrolyte adsorbed on the plastic core body 21 is electrostatically adsorbed on the surface of the plastic core body 21 by a chemical bond, it is not peeled off in the step of rinsing.

The polymer electrolyte solution is obtained by dissolving a polymer electrolyte in water or a mixed solvent of water and a water-soluble organic solvent. Examples of the water-soluble organic solvent that can be used include methanol, ethanol, propanol, acetone, dimethylformamide, and acetonitrile.

The concentration of the polymer electrolyte in the polymer electrolyte solution is usually about 0.01% by mass to 10% by mass. Further, the pH of the polymer electrolyte solution is not particularly limited. When the polymer electrolyte is used at a high concentration, the coating ratio of the core material 23 to the plastic core body tends to be high, and when the polymer electrolyte is used at a low concentration, the core material 23 is applied to the plastic core body 21 The tendency of the coverage rate to decrease.

When the core material 23 is covered by the alternate layering of the polymer electrolyte, the polymer electrolyte is wound around the core material 23, so that the bonding force is drastically improved. From the viewpoint of the bonding strength, a polymer electrolyte having a weight average molecular weight of 10,000 or more can also be used. The bonding strength increases together with the weight average molecular weight. However, if the weight average molecular weight is too high, the plastic core bodies 21 tend to aggregate easily.

The core material 23 may cover only one layer. If a plurality of layers are laminated, it is difficult to control the amount of the laminate.

The coverage of the core material 23 to the plastic core body 21 may be 5 area% to 60 area%, or may be 25 area% to 60 area%. The coverage of this case can be achieved by the pair of particles The center portion of the surface (two-dimensional image) (a circle having a radius of the radius of the plastic core body 21) was analyzed and calculated in the same manner as the coverage of the insulating sub-particles 1 described later. 80% of area is the case of substantially densest filling. In addition, the coverage ratio of the present embodiment is an average value of the coverage ratio obtained from 100 SEM photographs (100 particles) of the particles.

When electroless plating is performed, the plastic core body to which the core material 23 is adsorbed is dispersed in water by ultrasonic waves. Since the core material 23 is bonded to the surface of the plastic core body 21, it is advantageous that the core material 23 is less peeled off by the ultrasonic treatment. When the resonance frequency is 28 kHz to 38 kHz and the ultrasonic output power is 100 W, the core material 23 has a falling rate of 10% or less, or 3% or less.

(insulating subparticles)

The insulating sub-particles 1 coated on the mother particles 2 may be organic fine particles (organic particles), inorganic oxide fine particles (inorganic oxide particles), or organic-inorganic hybrid particles. The organic fine particles are excellent in conductivity. On the other hand, the inorganic oxide fine particles are excellent in that they are hard and are stable when subjected to physical impact, and are not easily dissolved in a solvent. An example of the insulating sub-particles coated on the mother particles 2 is shown below.

Examples of the organic fine particles include particles of the following resins: polyolefin resins such as polyethylene, polypropylene, and polybutadiene; acrylic resins such as polymethyl methacrylate; epoxy resins; and polyimine resins.

The inorganic oxide fine particles may be particles containing an oxide of cerium, aluminum, zirconium, titanium, cerium, zinc, tin, antimony or magnesium, and these particles may be used alone or in combination of two or more. Further, it may be a water-dispersed colloidal cerium oxide (SiO ₂ ) which is excellent in insulation and has a controlled particle size. Commercial products of such inorganic oxide fine particles include, for example, Snowtex, Snowtex UP (manufactured by Nissan Chemical Industries, Ltd.), and Quantron (PL) series (Fusan Chemical) Manufactured by an industrial company). In terms of insulation reliability, the concentration of alkali metal ions and alkaline earth metal ions in the dispersion solution may be 100 ppm or less, and the inorganic oxide fine particles may be hydrolyzed by a metal alkoxide, so-called sol-gel ( Sol-gel) method to manufacture.

The organic-inorganic hybrid particles are typically particles obtained by copolymerization of an acrylic resin and a polyfunctional alkoxysilane. When the ratio of the alkoxy decane is increased, the characteristics of the inorganic particles are further exhibited, and when the ratio of the acrylic resin is increased, the characteristics of the organic particles are more exhibited. The synthesis method is typically a dispersion polymerization or a precipitation polymerization.

The insulating subparticles 1 may have a functional group having a good reactivity with a functional group on the surface of the mother particle 2 such as a hydroxyl group, a stanol group or a carboxyl group, or a polymer electrolyte to be described later.

The particle size of the insulating subparticle 1 measured by the specific surface area conversion algorithm or the X-ray small angle scattering method by the Brunauer-Emmett-Teller (BET) method is 180 nm or more and 500 nm or less, and may be 200 nm. 480 nm, or 200 nm to 400 nm, or 250 nm to 400 nm. When the particle diameter of the insulating sub-particles 1 is 200 nm or more, there is a tendency that the insulating sub-particles adsorbed on the conductive particles 30 function as an insulating film. Produce a short circuit. On the other hand, when the particle diameter of the insulating sub-particles 1 is 500 nm or less, sufficient conductivity in the direction of connection in the connection tends to be obtained.

The particle diameter of the insulating subparticles 1 may be larger than the height H of the protrusions 23a.

The method of coating the insulating particles 1 on the mother particle 2 is a method of adsorbing the insulating particle 1 having a functional group on the surface to the mother particle 2 having a functional group on the surface.

The surface potential (kinetic potential, zeta potential) of the mother particles 2 having a functional group such as a hydroxyl group, a carboxyl group, an alkoxy group or an alkoxycarbonyl group is usually negative (if the pH is in the neutral range). On the other hand, the surface potential of the insulating subparticle 1 having a functional group such as a hydroxyl group is also usually negative. It is difficult to coat particles having a negative surface potential around the particles having a negative surface potential.

In this case, the method of coating the insulating particles 1 on the mother particles 2 may be a method of alternately laminating the polymer or the oligomer and the insulating sub-particles 1, or may alternately laminating the polymer electrolyte and the insulating sub-particles 1. method. The coating method includes the steps of: (1) dispersing the mother particles 2 having a functional group on the surface in the polymer electrolyte solution, adsorbing the polymer electrolyte on the surface of the mother particle 2, and performing a step of rinsing; and (2) The step of rinsing the mother particles 2 in the dispersion solution of the insulating sub-particles 1 and adsorbing the insulating sub-particles 1 on the surface of the mother particles 2 is carried out. As shown in FIG. 2(b), according to the above-described coating method, fine particles in which the insulating coating layer 3 is formed can be produced by laminating a polymer electrolyte and insulating subparticles 1 on the surface.

This method is called alternating layering (Layer-by-Layer) Assembly). The alternate layering method is a method of forming an organic film (Thin Solid Films, 210/211, p831 (1992)) published by G. Decher et al. in 1992. In the method, the substrate is alternately immersed in an aqueous solution of a positively charged polymer electrolyte (polycation) and a negatively charged polymer electrolyte (polyanion), whereby the layer is laminated on the substrate by electrostatic attraction. A composite film (alternating laminated film) is obtained by a group of adsorbed polycations and polyanions.

In the alternating layering method, the charge of the material formed on the substrate is attracted to the oppositely charged material in the solution by electrostatic attraction, whereby the film grows, so if the adsorption is performed and the charge is neutralized, it does not occur. Further adsorption. Therefore, if a certain saturation point is reached, the film thickness does not increase further. Lvov et al. have reported the following methods: applying an alternating layering method to microparticles, using a microparticle dispersion of cerium oxide, titanium oxide, and cerium oxide, and using an alternating layering method to laminate a surface having microparticles. A polymer electrolyte having an opposite charge (Langmuir, Vol. 13 (1997), p. 6195-6203). If this method is used, it is possible to alternately laminate insulating subparticles having a negative surface charge with polychlorinated diallyldimethylammonium (PDDA) or polyethyleneimine as a polycation having an opposite charge. (PEI) or the like to form a fine particle laminated film in which insulating sub-particles and a polymer electrolyte are alternately laminated.

After the mother particles are immersed in the dispersion liquid of the polymer electrolyte solution or the insulating subparticles, and then immersed in the insulating subparticle dispersion liquid or the polymer electrolyte solution having the opposite charge, the solvent may be eluted by using only the solvent. The excess polymer electrolyte solution or the insulating particle dispersion is washed. Used in this type of rinsing There are water, alcohol and acetone.

The polymer electrolyte solution is obtained by dissolving a polymer electrolyte in a mixed solvent of water or an organic solvent. Examples of the water-soluble organic solvent that can be used include methanol, ethanol, propanol, acetone, dimethylformamide, and acetonitrile.

The polymer electrolyte may be a polymer having a functional group which is ionized in an aqueous solution and has a charge in a main chain or a side chain, and may be a polycation. In addition, polycations can generally be used with positively chargeable (positively charged) functional groups such as polyamines, such as polyethyleneimine (PEI), polyallylamine hydrochloride (PAH), Polydiallyldimethylammonium chloride (PDDA), polyvinylpyridine (PVP), polylysine, polypropylene decylamine, and at least one or more copolymers containing the above.

Among the polymer electrolytes, polyethyleneimine has a high charge density and a strong bonding force. In these polymer electrolytes, in order to avoid electron migration or corrosion, alkali metal (Li, Na, K, Rb, and Cs) ions, alkaline earth metal (Ca, Sr, Ba, and Ra) ions and halide ions may not be contained. (fluoride ions, chloride ions, bromide ions, and iodide ions).

The polymer electrolytes may be dissolved in water or soluble in an organic solvent such as an alcohol. The weight average molecular weight of the polymer electrolyte varies depending on the type of the polymer electrolyte to be used, and may not be uniform, but may generally be 1,000 or more. It can also be around 1000~20000. When the weight average molecular weight is 1000 or more, the dispersibility of the mother particles 2 in the polymer electrolyte solution tends to be sufficient, and even if the particle diameter of the mother particles 2 is 3.0 μm or less, the aggregation tends to be suppressed. Further, the concentration of the polymer electrolyte in the solution may be usually from about 0.01% by mass to about 10% by mass. another Further, the pH of the polymer electrolyte solution is not particularly limited.

By using the polymer electrolyte film obtained in this way, the polymer electrolyte can be uniformly coated on the surface of the mother particle 2 without defects, and the insulation is ensured even when the circuit electrode spacing in the non-pressurized direction is narrow, and the electrical connection is ensured. The connection resistance between the circuit electrodes in the pressurizing direction is low and becomes good.

When the particle diameter of the mother particle 2 is small, the magnetic aggregation of the mother particle 2 becomes large, and it is difficult to adsorb the insulating subparticle 1 to the surface of the mother particle 2. In this case, when a polymer having a weight average molecular weight of 1,000 or more is disposed on the surface of the mother particle 2, there is a tendency to promote dispersion of the mother particles 2 in the insulating particle dispersion, and to insulate the daughter particles 1 to the mother particles. The adsorption of the surface of 2 becomes easy.

In addition, by adjusting the type, molecular weight, or concentration of the polymer electrolyte, it is possible to control the coverage of the insulating sub-particles 1 which are further coated with the polymer electrolyte on the surface of the mother particle 2.

Specifically, when a polymer electrolyte film having a high charge density such as polyethyleneimine is used, the coverage of the insulating subparticles 1 tends to be high, and polychloro diallyldimethylammonium chloride or the like is used. In the case of a polymer electrolyte film having a low charge density, the coverage of the insulating subparticles 1 tends to be low. In addition, when the molecular weight of the polymer electrolyte is large, the coverage of the insulating sub-particles 1 tends to be high, and when the molecular weight of the polymer electrolyte is small, the coverage of the insulating sub-particles 1 tends to be low. In the case where the polymer electrolyte solution is used at a high concentration, the coverage of the insulating subparticles 1 tends to be high, and when the polymer electrolyte solution is used at a low concentration, the insulator particles 1 are coated. The tendency to become lower.

The surface of the insulating subparticle 1 may be coated with a polymer or oligomer having a weight average molecular weight of 500 or more, and the weight average molecular weight may be 1000 or more, may be 1000 to 10,000, or may be 1000 to 4000. The surface of the insulating subparticle 1 may also be coated with a functional group-containing anthrone oligomer having a weight average molecular weight of 1,000 to 4,000. The polymer or oligomer may also have a functional group. The functional group may be a group reactive with the functional group on the surface of the mother particle or the above polymer electrolyte, and specifically, may be a glycidyl group, a carboxyl group or an isocyanate group, or may be a glycidyl group.

Thus, by bonding the chemically reactive polymer or the particles of the oligomer to each other, it is possible to cope with the reduction of the diameter of the mother particle 2 or the insulating subparticle 1 on the basis of obtaining a strong bond which was not previously present. Large diameter.

The coverage of the insulating subparticles 1 may be in the range of 10% by area to 50% by area, or may be in the range of 20% by area to 50% by area. When the coverage of the insulating sub-particles 1 is high, the insulating properties are high and the electrical conductivity is low. When the coverage of the insulating sub-particles 1 is low, the electrical conductivity is high and the insulating properties tend to be low. In addition, the coverage ratio is set to the total surface area of the center part of the surface of the mother particle 2 (circle of the diameter of the plastic core body 21 as diameter) W (The calculation based on the particle diameter of the mother particle is not included. The area of the protrusion is analyzed by image analysis of the central portion of the particle (a circle having a radius of the radius of the plastic core 21). When the surface area of the portion covered with the insulating particle 1 is set to P, P is /W×100 (area%) is expressed. In addition, in the present embodiment, the surface area P of the portion analyzed as being coated is an average value of surface areas determined from 100 SEM photographs of the particles.

Further, the coating unevenness (C.V.) of the insulating sub-particles 1 may be in the range of 0.3 or less. When the coating unevenness (C.V.) of the insulating subparticles 1 is 0.3 or less, the insulating property tends to be improved. In addition, the coverage unevenness (CV) is set to the standard deviation of the coverage ratio calculated based on image analysis of the center portion of the particle (a circle having a radius of the radius of the plastic core body 21) as When S is set to M, the value is expressed as S/M×100 (%). In addition, the standard deviation S and the average value M of the coverage ratio in the present embodiment were obtained from 100 SEM photographs of the particles.

The mother particles 2 are preferably covered by only one layer of the insulating subparticles 1. If a plurality of layers are stacked, it is sometimes difficult to control the amount of build-up.

By heating and drying the conductive particles 30 obtained in this manner, that is, the mother particles 2 coated with the insulating sub-particles 1, the bonding of the insulating sub-particles 1 and the mother particles 2 can be strengthened. The reason why the bond strength is enhanced is a chemical bond between the functional groups. The heating and drying temperature may be from 60 ° C to 200 ° C, and the heating time may be in the range of from 10 minutes to 180 minutes. When the heating temperature is 60° C. or higher or the heating time is 10 minutes or longer, the peeling of the insulating sub-particles 1 from the mother particles 2 tends to be suppressed, and the heating temperature is 200° C. or less or the heating time is 180. In the case of a minute or less, deformation of the conductive particles 30 tends to be suppressed.

The surface of the conductive particles 30 may be further subjected to an anthrone oligomer treatment. By performing the fluorenone oligomer treatment on the surface of the conductive particles 30, the insulation reliability of the conductive particles 30 tends to be further improved. The fluorenone oligomer used herein preferably has a compound having a hydrophobic functional group such as a methyl group or a phenyl group and a weight average molecular weight of about 500 to 5,000.

(Anisotropic conductive adhesive)

The conductive particles 30 are dispersed in the adhesive 31 to obtain a layer 32 containing conductive particles. The anisotropic conductive adhesive 40 may include only the conductive layer-containing layer 32, or may have a two-layer structure including a conductive particle-free layer formed on one surface of the conductive particle-containing layer 32. 33 may have a three-layer structure as shown in FIG. 2(a), and the three-layer structure further includes a layer 34 containing no conductive particles formed on the other surface of the conductive particle-containing layer 32. Further, as shown in FIG. 2(b) which is an enlarged cross-sectional view of FIG. 2(a), the conductive particles 30 include the mother particles 2 and an insulating coating formed on the surface of the mother particles 2 by the insulating sub-particles 1. Layer 3.

As the adhesive 31 used in the anisotropic conductive adhesive 40, a mixture of a thermally reactive resin and a hardener can be used. A mixture of an epoxy resin and a latent hardener may also be used as the subsequent agent. Examples of the latent curing agent include an imidazole-based, an anthraquinone-based, a boron trifluoride-amine complex, a phosphonium salt, an amine imide, a polyamine salt, and a dicyanodicimamine. In addition to this, a mixture of a radical reactive resin and an organic peroxide or an energy ray curable resin such as ultraviolet rays may be used as the adhesive.

The epoxy resin may be used alone or in combination of two or more kinds: a bisphenol type epoxy resin derived from epichlorohydrin and bisphenol A, bisphenol F or bisphenol AD; and epichlorohydrin and phenol novolak. Or an epoxy novolac resin derived from a cresol novolak; a naphthalene epoxy resin having a skeleton containing a naphthalene ring; glycidylamine, glycidyl ether, biphenyl or alicyclic, etc. having 2 in one molecule The above various glycidyl group-based epoxy compounds and the like.

In order to prevent electron migration, the epoxy resins may be high-purity products in which impurity ions (Na ⁺ , Cl ^{- ,} etc.) or hydrolyzable chlorine are reduced to 300 ppm or less.

In order to reduce the stress after the next or to improve the adhesion, a butadiene rubber, an acrylic rubber, a styrene-butadiene rubber, an anthrone rubber or the like may be mixed in the adhesive 31. Further, the anisotropic conductive adhesive 40 may be a paste (an anisotropic conductive adhesive paste) or a film (an anisotropic conductive adhesive film). In order to form a film, the adhesive 31 may contain a thermoplastic resin (film-forming polymer) such as a phenoxy resin, a polyester resin, or a polyamide resin. These film-forming polymers are also effective in alleviating the stress at the time of curing of the heat-reactive resin. The film-forming polymer may have a functional group such as a hydroxyl group in order to improve the adhesion.

The film formation is carried out, for example, by dissolving or dispersing a subsequent composition including a film-forming polymer such as a thermoreactive resin such as an epoxy resin or an acrylic rubber and a latent curing agent in an organic solvent. The liquid composition is applied to a release substrate, and the solvent is removed at a temperature lower than the activation temperature of the curing agent. In order to improve the solubility of the material, the solvent used at this time may be an aromatic hydrocarbon-based or oxygen-containing mixed solvent.

The thickness of the anisotropic conductive adhesive film is relatively determined in consideration of the particle diameter of the conductive particles 30 and the characteristics of the anisotropic conductive adhesive 40. In this case, the conductive layer-containing layer 32 may also be electrically non-conductive. The layer 33 of the particles is composed of two layers. The conductive particles 30 are efficiently trapped on the metal bump side by disposing the layer 33 containing no conductive particles on the metal bump side and the conductive particle-containing layer 32 on the glass side. Therefore, the layer 32 containing conductive particles can also be thin, and the layer 33 containing no conductive particles can also be included. The layer 32 of conductive particles is thick and highly fluid. Specifically, the thickness of the layer 32 containing the conductive particles is in the range of 3 μm to 15 μm, the thickness of the layer 33 containing no conductive particles is in the range of 7 μm to 20 μm, and the thickness of the layer 32 containing the conductive particles may also be The thickness of the entire anisotropic conductive adhesive film is 50% by mass or less.

In addition, in order to reinforce the adhesion to a glass substrate, ITO, or the like, it is also possible to have a three-layer structure in which a layer 34 containing no conductive particles having a thickness of 4 μm or less is further disposed on the glass electrode side. The fluidity of the layer 34 containing no conductive particles can also be high.

As shown in FIG. 2(b), the conductive particles 30 and the inorganic oxide particles 35 whose surface is hydrophobic may be dispersed in the adhesive 31 in the layer 32 containing conductive particles. By dispersing the conductive particles 30 and the inorganic oxide particles 35 whose surface is hydrophobic in the conductive material-containing layer 32 in the adhesive 31, the flow of the conductive particles 30 is suppressed by the inorganic oxide particles 35, and it is easy to conduct electricity. Since the particles 30 are caught on the metal bumps 42 and the ITO or indium zinc oxide (IZO) electrodes 44, high conductivity tends to be obtained in the pressurization direction.

An example of a method of producing the connection structure 50 using the anisotropic conductive adhesive 40 will be described with reference to FIGS. 3(a) and 3(b).

As shown in FIG. 3(a), the method of fabricating the connection structure 50 includes the steps of: first electrode (metal bump) on the first circuit substrate (IC wafer) 41 via the anisotropic conductive adhesive 40. 42. The second circuit electrode (Indium Tin Oxide (ITO) or Indium Zinc Oxide (IZO) electrode) 44 on the second circuit substrate (glass substrate) 43 is electrically connected. In the picture In 3 (a), the anisotropic conductive adhesive 40 is a three-layer structure in which a layer 33 containing no conductive particles, a layer 32 containing conductive particles, and a layer 34 containing no conductive particles are sequentially laminated. At this time, the IC wafer and the glass substrate are disposed such that the metal bumps 42 face the circuit electrodes 44 on the glass 43. Then, as shown in FIGS. 3(a) and 3(b), the IC wafer and the glass substrate are heated under pressure, and the members are laminated via the anisotropic conductive adhesive 40. The obtained connection structure 50 includes a first circuit member in which the first circuit electrode 42 is formed on the main surface of the first circuit board 41, and a second circuit electrode 44 on the main surface of the second circuit board 43. a second circuit member; and a first circuit disposed between the main surface of the first circuit substrate 41 and the main surface of the second circuit substrate 43 and disposed such that the first circuit electrode 42 and the second circuit electrode 44 face each other The circuit connecting member 40a to which the member and the second circuit member are connected to each other. The adhesive 31 in the anisotropic conductive adhesive 40 is melt-deformed by heat and pressure, and then hardened. Further, the conductive particles 30 in the anisotropic conductive adhesive 40 are crushed to become flat conductive particles. The circuit connecting member 40a includes a cured product of the anisotropic conductive adhesive 40. For example, when the anisotropic conductive adhesive 40 is composed of three layers, the cured product 33a containing the conductive layer-free layer 33 contains conductive particles. The cured product 32a of the layer 32 and the cured product 34a of the layer 34 containing no conductive particles. The opposing first circuit electrode 41 and the second circuit electrode 43 are electrically connected via flat conductive particles.

When the connection structure 50 is produced in this manner, the flow of the conductive particles is suppressed by the inorganic oxide particles 35, and the conductive particles are easily caught on the metal bumps 42, so that high conductivity can be obtained in the pressurization direction. For the metal bump 42 and the ITO or IZO electrode 44, the conductive oxide particles having a low content of the inorganic oxide particles 35 are not contained. The layer 34 is in contact, so that the embedding and adhesion can be maintained. When the trapping rate of the conductive particles 30 between the circuit electrodes in the pressurizing direction is increased, the ratio of the conductive particles flowing between the circuit electrodes in the non-pressurizing direction is reduced, so that the insulation between the circuit electrodes in the non-pressurizing direction is improved. Even if the coverage of the insulating coating layer 3 present on the surface of the conductive particles 30 is lowered, it is easy to ensure insulation. By reducing the coverage of the insulating coating layer 3, the conductivity between the circuit electrodes in the pressurizing direction is further improved.

[Examples]

(1) Production of mother particle 1

A plastic core 10 g was prepared, and the plastic core body contained a copolymer of divinylbenzene and acrylic acid having a cross-linking degree adjusted to have an average particle diameter of 2.6 μm. The above plastic core body has a carboxyl group on its surface. The hardness of the plastic core (compressive elastic modulus at 20% change in particle diameter at 200 ° C, 20% K value) was 280 kgf/mm ² .

A 30% by mass aqueous solution of polyethyleneimine (manufactured by Wako Pure Chemical Industries, Ltd.) having a molecular weight of 70,000 was diluted to 0.3% by mass with ultrapure water. 10 g of the above-mentioned plastic core body was added to 300 mL of this 0.3% by mass aqueous solution of polyethyleneimine, and the mixture was stirred at room temperature for 15 minutes. The plastic core was taken out by filtration using a membrane filter (manufactured by Millipore) having a pore diameter of φ 3 μm, and the taken plastic core was placed in 300 g of ultrapure water and stirred at room temperature. 5 minutes. Then, the plastic core body was taken out by filtration using a membrane filter (manufactured by Millipore) having a pore diameter of φ 3 μm. The plastic core on the membrane filter was washed twice with 200 g of ultrapure water, and the unadsorbed polyethyleneimine was removed to obtain a plastic core body adsorbed with polyethyleneimine.

The colloidal ceria dispersion having an average particle diameter of 100 nm was diluted with ultrapure water to obtain a 0.33 mass% cerium oxide particle dispersion (total amount of cerium oxide: 1 g). The above-mentioned plastic core body to which polyethyleneimine was adsorbed was added thereto, and stirred at room temperature for 15 minutes. Thereafter, the plastic core body was taken out by filtration using a membrane filter (manufactured by Millipore) having a pore diameter of φ 3 μm. Since cerium oxide was not extracted from the filtrate, it was confirmed that substantially all of the cerium oxide particles were adsorbed on the plastic core. The plastic core body to which the cerium oxide particles were adsorbed was placed in 200 g of ultrapure water, and stirred at room temperature for 5 minutes. Thereafter, the plastic core body was taken out by filtration using a membrane filter (manufactured by Millipore) having a pore diameter of φ 3 μm, and the plastic core body on the membrane filter was washed with 200 g of ultrapure water. Times. The washed plastic core body was heated at 80 ° C for 30 minutes, and heated at 120 ° C for 1 hour, thereby drying to obtain a plastic core body (composite particles) having adsorbed cerium oxide particles on the surface.

1 g of the above composite particles was taken, and an ultrasonic wave having a resonance frequency of 28 kHz and an output of 100 W was irradiated for 15 minutes, and then added to an Atotech Neoganth 834 containing 8 mass% of a palladium catalyst. 100 mL of a palladium catalyst solution (manufactured by Atotech Japan Co., Ltd., trade name) was stirred at 30 ° C for 30 minutes while irradiating ultrasonic waves. Thereafter, the composite particles were taken out by filtration using a membrane filter (manufactured by Millipore Co., Ltd.) having a pore diameter of φ 3 μm, and the extracted composite particles were washed with water. The water-washed composite particles were added to a 0.5% by mass dimethylamine borane solution adjusted to a pH of 6.0 to obtain surface-activated composite particles.

The surface-activated composite particles were immersed in distilled water and ultrasonically dispersed to obtain a suspension. While stirring the suspension at 50 ° C, 50 g / L of nickel sulfate hexahydrate, 20 g / L of sodium hypophosphite monohydrate, 2.5 g / L of dimethylamine borane and 50 g of citric acid were mixed. /L, an electroless plating solution A having a pH adjusted to 5.0 was gradually added to form an electroless nickel/phosphorus alloy layer on the composite particles. The nickel/phosphorus alloy layer contains about 7 mass% of phosphorus. The film thickness of nickel was measured by sampling and atomic absorption, and the addition of the electroless plating solution A was stopped when the film thickness of the nickel plating layer reached 750 Å. After filtration, it was washed with 100 mL of pure water for 60 seconds to obtain mother particles 1 having protrusions on the surface and having a nickel/phosphorus alloy layer as a plating layer. The height of the protrusion on the surface of the mother particle 1 was observed by SEM, and as a result, it was approximately the same as the particle size of the cerium oxide particle adsorbed on the plastic core body, and was 100 nm. The coverage of the protrusions was measured by image analysis of the SEM image, and as a result, it was about 40 area%. Further, the saturation magnetization per unit volume of the mother particle 1 was determined in the following manner. When the saturation magnetization was measured, a vibrating sample magnetometer (VSM: Vibrating Sample Magnetometer, BHV-525 manufactured by Riken Electronics Co., Ltd.) was used. In addition, the calibration of the magnetometer was performed in advance using a standard sample (nickel). The mother particle 1 is weighed in a dedicated container and mounted on a sample holder. The sample holder was mounted on the magnetometer body and measured at a temperature of 20 ° C (constant temperature), a maximum applied magnetic field of 20,000 Oe (1.6 MA/m), and a speed of 3 min/loop, thereby obtaining magnetization. curve. The saturation magnetization (emu) was obtained from the obtained magnetization curve. On the other hand, the specific gravity of the mother particle 1 was measured using a hydrometer (Accupyc 1330 manufactured by Shimadzu Corporation). The saturation magnetization per unit volume of the mother particle 1 was calculated from the saturation magnetization of the mother particle 1, the mass of the mother particle 1 for measuring the saturation magnetization, and the specific gravity of the mother particle 1. As a result, it was 0.5 emu/cm ³ .

(2) Production of mother particle 2

In the same manner as the mother particle 1 except that the dispersion of the colloidal cerium oxide having an average particle diameter of 100 nm is used instead of the dispersion of the nickel nitrite having an average particle diameter of 100 nm, the protrusion (core nickel) is produced in the same manner as the mother particle 1 Mother particle 2. The height and the coverage of the protrusions were measured by image analysis of the SEM image. As a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 40 area%. The saturation magnetization per unit volume was measured and found to be 44.5 emu/ Cm ³ .

(3) Production of mother particle 3

A mother particle 3 having a protrusion (core material nickel) was produced in the same manner as the mother particle 2 except that a plastic core body having an average particle diameter of 2.8 μm was used instead of the plastic core body having an average particle diameter of 2.6 μm. The height and coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 40 area%. Further, the saturation magnetization per unit volume of the mother particles 3 was measured and found to be 44.3 emu/cm ³ .

(4) Production of mother particles 4

A mother particle 4 having a protrusion (core material nickel) was produced in the same manner as the mother particle 2 except that a plastic core body having an average particle diameter of 2.3 μm was used instead of the plastic core body having an average particle diameter of 2.6 μm. The height and coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 40 area%. Further, the saturation magnetization per unit volume of the mother particles 4 was measured and found to be 44.7 emu/cm ³ .

(5) Production of mother particles 5

A mother particle 5 having a protrusion (core material nickel) was produced in the same manner as the mother particle 2 except that a plastic core body having an average particle diameter of 2.1 μm was used instead of the plastic core body having an average particle diameter of 2.6 μm. The height and coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 40 area%. Further, the saturation magnetization per unit volume of the mother particles 5 was measured and found to be 44.8 emu/cm ³ .

(6) Production of mother particles 6

A mother particle 6 having a protrusion (core material nickel) was produced in the same manner as the mother particle 2 except that a plastic core body having an average particle diameter of 1.8 μm was used instead of the plastic core body having an average particle diameter of 2.6 μm. The height and coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 40 area%. Further, the saturation magnetization per unit volume of the mother particles 6 was measured and found to be 44.9 emu/cm ³ .

(7) Production of mother particle 7

A mother particle 7 having a protrusion (core material nickel) was produced in the same manner as the mother particle 2 except that a plastic core body having an average particle diameter of 3.0 μm was used instead of the plastic core body having an average particle diameter of 2.6 μm. The height and coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 40 area%. Further, the saturation magnetization per unit volume of the mother particles 7 was measured and found to be 44.5 emu/cm ³ .

(8) Production of mother particles 8

The mother particles 8 having protrusions (core nickel) were produced in the same manner as the mother particles 2 except that the amount of the nickel fine particle dispersion having an average particle diameter of 100 nm was changed. The height and the coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 44.5 area%. Further, the saturation magnetization per unit volume of the mother particles 8 was measured and found to be 49.5 emu/cm ³ .

(9) Production of mother particles 9

The mother particles 9 having protrusions (core nickel) were produced in the same manner as the mother particles 2 except that the amount of the nickel fine particle dispersion having an average particle diameter of 100 nm was changed. The height and coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 27.3 area%. Further, the saturation magnetization per unit volume of the mother particles 9 was measured and found to be 29.8 emu/cm ³ .

(10) Production of mother particles 10

The mother particles 10 having protrusions (core nickel) were produced in the same manner as the mother particles 2 except that the amount of the nickel fine particle dispersion having an average particle diameter of 100 nm was changed. The height and the coverage of the protrusions were measured by image analysis of the SEM image, and as a result, the height of the protrusions was 100 nm, and the coverage of the protrusions was about 9.1 area%. Further, the saturation magnetization per unit volume of the mother particles 10 was measured and found to be 9.9 emu/cm ³ .

(Production of anthrone ketone oligomer 1)

A solution was prepared by dissolving 50 g of triethoxyphenylnonane in 10 g of methanol. While stirring the solution, a solution of 6 g of distilled water and 0.5 g of acetic acid was added, and the mixture was heated at 80 ° C for a certain period of time to carry out hydrolysis and polycondensation reaction. After cooling to 0 °C for a while, add dropwise 6 g of tetraethoxy decane was stirred at room temperature for 2 hours to obtain an anthrone oligopolymer having a phenyl group in the oxoxane skeleton and having a trifunctional end. The obtained anthrone ketone oligomer had a weight average molecular weight of 1,100. Methanol was added to the obtained fluorenone oligomer solution to prepare a treatment liquid having a solid content of 20% by mass. Further, the weight average molecular weight was measured by Gel Permeation Chromatography (GPC) using a standard curve of standard polystyrene, and the measurement conditions were as follows.

<GPC condition>

Equipment used: Hitachi L-6000 [Hitachi Manufacturing Co., Ltd.]

Pipe column: Gelpack GL-R420+Gelpack GL-R430+Gelpack GL-R440 (3 in total) [all manufactured by Hitachi Chemical Co., Ltd., trade name]

Dissolution: tetrahydrofuran

Measuring temperature: 40 ° C

Flow rate: 1.75 mL/min

Detector: L-3300RI [Hitachi Manufacturing Co., Ltd.]

(Production of anthrone ketone oligomer 2)

In a glass flask equipped with a stirring device, a condenser, and a thermometer, 118 g of 3-glycidoxypropyltrimethoxydecane and 5.9 g of methanol were prepared, and 5 g of activated clay and 4.8 g of distilled water were added to the obtained solution. The mixture was stirred at 75 ° C for a certain period of time to obtain an anthrone oligomer having a weight average molecular weight of 1300. The resulting anthrone oligomer has a methoxy or stanol group as a terminal functional group reactive with a hydroxyl group. Methanol was added to the obtained fluorenone oligomer solution to prepare a treatment liquid having a solid content of 20% by mass.

(Production of Insulating Subparticle 1)

Composition of 3-propenyloxypropyltrimethoxydecane (73.13 mass%), methyl acrylate (5.42 mass%), methacrylic acid (19.5 mass%), and azobisisobutyronitrile (1.95 mass%) To make microparticles. Each of the above compounds was added in a 500 mL flask (adjusted concentration), 350 g of acetonitrile as a solvent was added, and dissolved oxygen was replaced with nitrogen (100 mL/min) for 1 hour, and then a dissolved oxygen meter was used (Iijima Electronics). Industrial Dometer (B506)) was used to measure the dissolved oxygen amount and found to be 0.07 mg/mL. Thereafter, the mixture was heated and stirred at a water bath temperature of 80 ° C for about 6 hours using a stirrer to obtain an organic-inorganic mixed particle dispersion. Then, the particles in the obtained dispersion were sedimented by a centrifugal separator, and after removing the supernatant, acetonitrile was again added to redisperse the particles. Thereafter, an aqueous ammonia solution (28% by mass) of 1.76 g (with respect to the amount of added carboxyl groups of the particles) was added as a particle hardening catalyst to crosslink the particles. Then, the particles were again sedimented by centrifugation, and the supernatant was removed to redisperse the particles in methanol. The obtained organic-inorganic hybrid particles were used as the insulating sub-particles 1. The average particle diameter of the insulating subparticles 1 was measured by SEM and found to be 300 nm.

(Production of Insulating Subparticle 2)

The insulating sub-particles 2 having an average particle diameter of 180 nm were produced by the same method as the insulating sub-particles 1 except that the concentration (composition of the compounds) of the compound at the time of particle formation was changed.

(Production of Insulating Particle 3)

In addition to changing the concentration (composition of the same) of the compound at the time of particle production, The insulating sub-particles 3 having an average particle diameter of 220 nm were produced in the same manner as the insulating sub-particles 1.

(Production of Insulating Subparticle 4)

The insulating sub-particles 4 having an average particle diameter of 480 nm were produced by the same method as the insulating sub-particles 1 except that the concentration (composition of the compounds) of the compound at the time of particle formation was changed.

(Production of Insulating Subparticle 5)

The insulating sub-particles 5 having an average particle diameter of 550 nm were produced by the same method as the insulating sub-particles 1 except that the concentration (composition of the compounds) of the compound at the time of particle formation was changed.

(conductive particles 1)

A reaction liquid was prepared by dissolving 8 mmol of thioglycolic acid in 200 mL of methanol. Then, 10 g of the mother particles were added to the above reaction liquid, and stirred at room temperature for 2 hours using a three-in-one motor (Three-One Motor) and a stirring blade having a diameter of 45 mm. After washing with methanol, the mother particle 1 was filtered with a membrane filter (manufactured by Millipore Co., Ltd.) having a pore diameter of φ 3 μm to obtain 10 g of mother particles having a carboxyl group on the surface.

Then, a 30% by mass aqueous solution of polyethyleneimine (manufactured by Wako Pure Chemical Industries, Ltd.) having a molecular weight of 70,000 was diluted with ultrapure water to obtain a 0.3% by mass aqueous solution of polyethyleneimine. The above-mentioned 10 g of the mother particles having a carboxyl group was added to a 0.3% by mass aqueous solution of polyethyleneimine, and stirred at room temperature for 15 minutes. Then, the mother particle was filtered using a membrane filter (manufactured by Millipore) having a pore diameter of φ 3 μm. 1. Put in 200 g of ultrapure water and stir at room temperature for 5 minutes. Further, the mother particle 1 was filtered with a membrane filter (manufactured by Millipore Corporation) having a pore diameter of φ 3 μm. The mother particle 1 having an amine group-containing polymer on the surface was produced by washing twice with 200 g of ultrapure water on the above-mentioned membrane filter to remove unadsorbed polyethyleneimine.

Then, the anthrone ketone oligomer 2 is coated on the insulating subparticles 1 to prepare a methanol dispersion medium of the insulating subparticles 1 having a glycidyl group-containing oligomer on the surface.

Then, the mother particle 1 treated with polyethyleneimine is immersed in isopropyl alcohol, and added dropwise to the methanol dispersion medium of the insulating subparticle 1 having the glycidyl group-containing oligomer on the surface, thereby making insulation. The coverage of the proton particles is 30% by area of conductive particles. The coverage rate is adjusted by the amount of addition. Then, the entire conductive particles obtained are treated with the fluorenone oligomer 1 to be washed, and the surface is hydrophobized. Thereafter, the film was dried at 80 ° C for 30 minutes, and dried by heating at 120 ° C for 1 hour to prepare conductive particles 1.

(conductive particles 2)

The conductive particles 2 were produced in the same manner as the conductive particles 1 except that the mother particles 2 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 3)

The conductive particles 3 were produced in the same manner as the conductive particles 1 except that the mother particles 3 were used instead of the mother particles 1. Insulation particle particle coverage is 30 areas %.

(conductive particles 4)

The conductive particles 4 were produced in the same manner as the conductive particles 1 except that the mother particles 4 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 5)

The conductive particles 5 were produced in the same manner as the conductive particles 1 except that the mother particles 5 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 6)

The conductive particles 6 were produced in the same manner as the conductive particles 1 except that the mother particles 6 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 7)

The conductive particles 7 were produced by the same method as the conductive particles 1 except that the mother particles 7 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 8)

The conductive particles 8 were produced by the same method as the conductive particles 1 except that the mother particles 8 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 9)

The conductive particles 9 were produced by the same method as the conductive particles 1 except that the mother particles 9 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 10)

The conductive particles 10 were produced by the same method as the conductive particles 1 except that the mother particles 10 were used instead of the mother particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 11)

The conductive particles 11 were produced by the same method as the conductive particles 2 except that the insulating sub-particles 2 were used instead of the insulating sub-particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 12)

The conductive particles 12 were produced by the same method as the conductive particles 2 except that the insulating sub-particles 3 were used instead of the insulating sub-particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 13)

The conductive particles 13 were produced by the same method as the conductive particles 2 except that the insulating sub-particles 4 were used instead of the insulating sub-particles 1. The coverage of the insulating subparticles was 30 area%.

(conductive particles 14)

The conductive particles 14 were produced by the same method as the conductive particles 2 except that the insulating sub-particles 5 were used instead of the insulating sub-particles 1. Insulating particle The coverage is 30 area%.

(Example 1)

100 g of phenoxy resin (manufactured by Union Carbide, trade name, PKHC) and acrylic rubber (40 parts of butyl acrylate, 30 parts of ethyl acrylate, 30 parts of acrylonitrile, and glycidyl methacrylate) Three parts of the copolymer, molecular weight: 850,000, and 75 g were dissolved in 300 g of a solvent obtained by mixing ethyl acetate and toluene in a weight ratio of 1:1 to obtain a 30% by mass solution. Then, a liquid epoxy (epoxy equivalent weight: 185, manufactured by Asahi Kasei Epoxy Co., Ltd., Novacure HX-3941) 300 g and liquid epoxy resin containing a microcapsule type latent curing agent ( An oil solution was prepared by adding 400 g of YL980) to the above solution and stirring it.

Then, the cerium oxide slurry is added to the adhesive solution 1, and the cerium oxide slurry is a particle size of 14 nm in such a manner that the cerium oxide solid content is 5% by mass relative to the adhesive solid content. Yttrium oxide (R202, manufactured by Aerosil Co., Ltd., Japan) was obtained by solvent dispersion.

The conductive particles 1 were ultrasonically dispersed in 10 g of a solvent obtained by mixing ethyl acetate and toluene in a mass ratio of 1:1. Ultrasonic dispersion was performed in an ultrasonic bath at 38 kHz, 400 W, and 20 L (test apparatus: US107 Fujimoto, trade name) for 1 minute.

The dispersion liquid was dispersed in the adhesive solution 1 to prepare an adhesive solution 2. The adhesive solution 2 was applied onto a separator (an anthraquinone-treated polyethylene terephthalate film having a thickness of 40 μm) by a roll coater, and dried at 90 ° C for 10 minutes to prepare a thickness of 10 An anisotropic conductive adhesive film A of μm. The anisotropic conductive adhesive film contains 100,000/mm ² particles per unit area.

Further, the adhesive solution 1 was applied onto a separator (an anthraquinone-treated polyethylene terephthalate film having a thickness of 40 μm) by a roll coater, and dried at 90 ° C for 10 minutes to prepare a thickness of 3 μm anisotropic conductive adhesive film B.

Further, the adhesive solution 1 was applied onto a separator (an anthraquinone-treated polyethylene terephthalate film having a thickness of 40 μm) by a roll coater, and dried at 90 ° C for 10 minutes to prepare a thickness of 10 μm anisotropic conductive adhesive film C.

Then, the anisotropic conductive adhesive film B, the anisotropic conductive adhesive film A, and the anisotropic conductive adhesive film C were sequentially laminated to form an anisotropic conductive adhesive film D including three layers.

Then, using the produced anisotropic conductive adhesive film D, gold bumps were attached as shown below (area: 30 μm × 90 μm, space (8 μm), height: 15 μm, bumps The number of 362) wafers (1.7 mm × 1.7 mm, thickness: 0.5 μm) was connected to a circuit-attached glass substrate (thickness: 0.7 mm).

After attaching the anisotropic conductive adhesive film D to the glass substrate with a circuit at 80 ° C and 0.98 MPa (10 kgf / cm ² ), the separator is peeled off, and the wafer with the gold bump is attached. The alignment of the bumps with the circuit electrodes of the circuit-attached glass substrate. Then, heating and pressurization were performed from above the wafer under conditions of 190 ° C, 40 g / bump, and 10 seconds to form a formal connection. The evaluation results are shown in Table 1.

(Example 2)

In addition to the use of the conductive particles 2 instead of the conductive particles 1, the use and the embodiment 1 The same method is used to make the connection structure. The evaluation results are shown in Table 1.

(Example 3)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 3 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Example 7)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 4 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Example 8)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 5 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Comparative Example 3)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 6 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Comparative Example 4)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 7 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Comparative Example 5)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 8 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Example 4)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 9 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Example 5)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 10 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Example 9)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 11 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Example 6)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 12 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Embodiment 10)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 13 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Comparative Example 8)

A bonded structure was produced in the same manner as in Example 1 except that the conductive particles 14 were used instead of the conductive particles 1. The evaluation results are shown in Table 1.

(Insulation resistance test and on-resistance test)

The connection structures produced in Examples 1 to 10 and Comparative Examples 3 to 5 and Comparative Example 8 were subjected to an insulation resistance test and an on-resistance test. The anisotropic conductive adhesive film is important in that the insulation resistance between the wafer electrodes (bumps) in the non-pressurized direction is high, and the on-resistance between the wafer electrodes and the glass electrodes in the pressurizing direction is low. In the insulation resistance test, the insulation resistance values between the wafer electrodes of 20 samples were measured, and the average value of the minimum values of the respective samples was calculated. In addition, the yield when the insulation resistance value >10 ⁹ (Ω) is considered to be good is calculated.

Further, the on-resistance values between the wafer electrodes and the glass electrodes of the 14 samples were measured, and the average value thereof was calculated. The on-resistance value was measured after the initial stage and the moisture absorption heat resistance test (500 hours at a temperature of 85 ° C and a humidity of 85%).

(protrusion coverage rate)

The SEM image of 100 mother particles is prepared, and the area occupied by the protrusions present in the central portion of the image (in the circle having the radius of the radius of the plastic core body) is measured by image analysis of the contour of the concave portion of the protrusion, The coverage of the protruding portion is calculated in the form of the area occupied by the protruding portion of the area of the entire central portion.

(Coated unevenness of insulating particle (C.V.))

An SEM image of 100 conductive particles was prepared, and the area occupied by the insulating sub-particles present in the central portion of the image (in a circle having a radius of the radius of the plastic core) was measured by image analysis of the contour of the insulating sub-particles. The coating unevenness of the insulating sub-particles was calculated.

Whether or not the evaluation result obtained by the on-resistance after the insulation resistance and the moisture absorption heat resistance test is satisfied by the following indexes satisfies the characteristics required for the connection structure of the circuit board.

AA: Fully satisfied

A: Satisfied

B: Satisfied but worse than A

C: Unable to use

Example 1 is an example in which ceria was used as a core material. Due to plating The phosphorus content is high and the protruding core material is a non-magnetic material, so the saturation magnetization of the mother particles shows a low value. Therefore, when the insulating subparticles are coated, the mother particles are less likely to aggregate, and the insulating subparticles have a small coating unevenness (C.V.), so that the insulating properties are particularly excellent. Example 2, Example 3, Example 7 and Example 8 are examples in which nickel was used as a protruding core material. Therefore, the saturation magnetization of the mother particles showed a higher value than that of Example 1. The smaller the particle diameter of the mother particles, the more likely the aggregation tends to be caused by the influence of magnetic properties, and as a result, the coating unevenness (C.V.) becomes large, and the insulation property is lowered. When the particle diameter of the mother particles is less than 2 μm, magnetic coagulation is likely to occur, and the insulation resistance value is low. Further, since the particle diameter of the mother particles was small, the conductivity was also low (Comparative Example 3).

When the particle diameter of the mother particles exceeds 3 μm, the insulation properties are largely lowered (Comparative Example 4). Further, when the saturation magnetization of the mother particles exceeds 45 emu/cm ³ (Comparative Example 5), magnetic aggregation is likely to occur, and the insulation resistance is lowered. This phenomenon tends to occur particularly when the particle diameter of the mother particles is 3 μm or less. Further, when the coverage of the protrusions is low (Example 4, Example 5), the saturation magnetization of the mother particles is small, and the insulation property is excellent. When the particle diameter of the insulating sub-particles is less than 200 nm (Example 9), the insulating properties are lowered. In addition, when the particle diameter of the insulating sub-particles is close to 500 nm (Example 10), insulation and conductivity tend to be lowered, and if the particle diameter of the insulating sub-particles exceeds 500 nm (Comparative Example 8), it cannot be used as a connection. Construct.

1‧‧‧Insulators

2‧‧‧ mother particles

11‧‧‧Polymers or oligomers

21‧‧‧Plastic core

22‧‧‧ plating layer

23‧‧‧ core material

23a‧‧‧ Protrusion

24‧‧‧ polymer electrolyte membrane

30‧‧‧Electrical particles

H‧‧‧ Height

Claims (10)

a conductive particle comprising: a mother particle having a plastic core body and a plating layer covering the surface of the plastic core body and containing at least a nickel/phosphorus alloy layer; and insulating subparticles covering the surface of the mother particle; Further, the particle diameter of the mother particles is 2.0 μm or more and 3.0 μm or less, the saturation magnetization of the mother particles is 45 emu/cm ³ or less, and the particle diameter of the insulating sub-particles is 180 nm or more and 500 nm or less. The conductive particle according to claim 1, wherein the mother particle has a protrusion on a surface, and a height of the protrusion is smaller than a particle diameter of the insulating particle. The conductive particles according to claim 1 or 2, wherein the mother particles have protrusions on a surface thereof, and the protrusions are covered by the surface of the plastic core body to which the core material is adhered by the plating layer. Formed, the core material is a non-magnetic material. The conductive particles according to any one of the items 1 to 3, wherein the nickel/phosphorus alloy layer has a phosphorus content of 1.0% by mass or more and 10.0% by mass or less. The conductive particles according to any one of the first to fourth aspect, wherein the insulating subparticles have a coverage ratio of 20% to 50%, and the insulating subparticles have a coating unevenness C.V. of 0.3 or less. The conductive particles according to any one of the items 1 to 5, wherein the insulating sub-particles have a layer containing a polymer or an oligomer having a weight average molecular weight of 1,000 or more. The conductive particles according to any one of claims 1 to 6, wherein the mother particles further have a layer containing a polymer or oligomer having a weight average molecular weight of 1,000 or more. The conductive particles according to any one of claims 1 to 7, wherein the insulating sub-particles have a particle diameter of 200 nm or more and 400 nm or less. An anisotropic conductive adhesive film obtained by dispersing the conductive particles according to any one of the first to eighth aspects of the invention in an adhesive. A connection structure of a circuit member, comprising: a first circuit member having a first circuit electrode formed on a main surface of the first circuit substrate; and a second circuit electrode formed on a main surface of the second circuit substrate a circuit member; and the first circuit is disposed between the main surface of the first circuit board and the main surface of the second circuit board, and the first circuit electrode and the second circuit electrode are disposed to face each other a circuit connecting member to which the member and the second circuit member are connected to each other; and the circuit connecting member includes the cured product of the anisotropic conductive adhesive film according to claim 9 of the invention, the first circuit electrode facing the first and the first The two circuit electrodes are flat Conductive particles are electrically connected.