TWI598889B - Conductive particles with insulating particles, conductive material, and connection structure - Google Patents

Description

Conductive particles, conductive materials and bonded structures with insulating particles

The present invention relates to a conductive particle having insulating particles in which insulating particles are disposed on a surface of a conductive particle. Moreover, the present invention relates to a conductive material and a connection structure using the above-described conductive particles with insulating particles.

Paste or film anisotropic conductive materials are well known. In the anisotropic conductive material, a plurality of conductive particles are dispersed in a binder resin or the like.

In order to obtain various connection structures, the anisotropic conductive material is used, for example, for connection between a flexible printed substrate and a glass substrate (FOG (Film on Glass), coated glass), and connection between a semiconductor wafer and a flexible printed substrate (COF (Chip on) Film), semiconductor wafer and glass substrate connection (COG (Chip on Glass), glass flip chip), and flexible printed circuit board and glass epoxy substrate (FOB (Film on Board), coated plate )Wait.

In addition, as the conductive particles, conductive particles having insulating particles in which insulating particles are disposed on the surface of the conductive particles may be used.

As an example of the conductive particles with the insulating particles, Patent Document 1 below discloses conductive particles with insulating particles coated with insulating particles as one of the surfaces of the conductive particles. Regarding the conductive particles with the insulating particles, the mass of the insulating particles is 2/1000 to 26/1000 of the mass of the conductive particles. Further, in the conductive particles with insulating particles shown in the examples and the comparative examples of Patent Document 1, the mass of the insulating particles is in the range of 9/1000 to 30/1000 of the mass of the conductive particles.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4380327

When an anisotropic conductive material containing conductive particles with insulating particles as described in Patent Document 1 is used for electrical connection between electrodes, it is difficult to efficiently arrange a plurality of conductive particles. In the case of electrodes. The conductive particles are likely to be disposed not only in the line (L, line) where the electrode is formed but also in the space (S) where the electrode is not formed. Therefore, it is necessary to use a large amount of conductive particles on the premise that the conductive particles are also disposed in the space. Further, as a result of the arrangement of the conductive particles in the space, there is a problem that insulation defects are likely to occur.

Moreover, in recent years, with the miniaturization and high performance of electronic equipment, the L/S of the electrode width and the inter-electrode width are further narrowed. When such an electrode having a narrow L/S is electrically connected to each other, it is difficult to accurately arrange the conductive particles with insulating particles on the electrode.

Moreover, in the anisotropic conductive material containing the conductive particles with the insulating particles attached as described in Patent Document 1, the anisotropic conductive material has a higher dispersibility of the conductive particles with insulating particles. Low situation.

An object of the present invention is to provide an electrically conductive particle containing insulating particles in which conductive particles are efficiently disposed on an electrode when used for electrical connection between electrodes, and using the insulating particles A conductive material of a conductive particle and a bonded structure.

An object of the present invention is to provide a conductive material having insulating particles which can be improved in dispersibility in a conductive material, and a conductive material and a connecting structure using the conductive particles with the insulating particles.

According to a broad aspect of the present invention, there is provided a conductive particle containing insulating particles, comprising: at least a conductive particle having a conductive portion on a surface thereof; and a plurality of insulating particles disposed on a surface of the conductive particle, The ratio of the weight of the entire insulating particles to the weight of the conductive particles exceeds 0.03 and is 0.25 or less.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles are organic particles or inorganic particles, and when the insulating particles are organic particles, the weight of the insulating particles as a whole When the ratio of the weight of the conductive particles is more than 0.03 to 0.12 or less, when the insulating particles are inorganic particles, the ratio of the weight of the entire insulating particles to the weight of the conductive particles is 0.08 or more. 0.25 or less.

In a specific aspect of the conductive particles with insulating particles of the present invention, the insulating particles are organic particles, and the ratio of the weight of the insulating particles as a whole to the weight of the conductive particles exceeds 0.03 and is 0.12. the following.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the insulating particles are inorganic particles, and the ratio of the weight of the insulating particles as a whole to the weight of the conductive particles is 0.08 or more and 0.25. the following.

In a specific aspect of the conductive particles with insulating particles of the present invention, the conductive particles have a substrate particle and a conductive portion disposed on a surface of the substrate particle.

In a specific aspect of the conductive particles with insulating particles of the present invention, the ratio of the total weight of the insulating particles to the weight of the substrate particles exceeds 0.086 and does not reach 0.600.

In a specific aspect of the conductive particles with insulating particles of the present invention, the conductive particles have a plurality of protrusions on a surface of the conductive portion.

In a specific aspect of the conductive particles with insulating particles of the present invention, the insulating particles have an average particle diameter larger than an average height of the protrusions.

In a specific aspect of the conductive particles with insulating particles of the present invention, the conductive particles with the insulating particles are dispersed in a binder resin to be used as a conductive material.

In a specific aspect of the conductive particles with insulating particles of the present invention, the conductive particles with the insulating particles are used for electrical connection between the electrodes, and between the electrodes of the space where the electrode is not formed. The minimum width is 20 μm or less.

According to a broad aspect of the present invention, there is provided a conductive material comprising the above-mentioned conductive particles with insulating particles and a binder resin.

According to a broad aspect of the present invention, a connection structure comprising: a first connection member having a first electrode on a surface thereof, a second connection member having a second electrode on a surface thereof, and a first connection are connected a connection portion between the target member and the second connection target member; wherein the connection portion is formed of the conductive particles with the insulating particles or the conductive material including the conductive particles with the insulating particles and the binder resin; Further, the first electrode and the second electrode are electrically connected by the conductive particles of the conductive particles with insulating particles.

In a specific aspect of the connection structure of the present invention, the minimum value of the inter-electrode width of the space where the portion of the first electrode is not formed and the minimum value of the inter-electrode width of the space where the second electrode is not formed It is 20 μm or less.

The conductive particles with insulating particles of the present invention include conductive particles having a conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the conductive particles, and further, the weight of the insulating particles as a whole is relatively When the ratio of the weight of the conductive particles exceeds 0.03 and is 0.25 or less, when the conductive particles with insulating particles of the present invention are used for electrical connection between electrodes, the conductive particles can be efficiently used. Configured on the electrode.

1‧‧‧ Conductive particles with insulating particles

2‧‧‧Electrical particles

3‧‧‧Insulating particles

11‧‧‧Substrate particles

12‧‧‧Electrical Department

21‧‧‧Electrically conductive particles with insulating particles

22‧‧‧Electrical particles

31‧‧‧Electrical Department

32‧‧‧ core material

33‧‧‧ Protrusion

41‧‧‧Electrically conductive particles with insulating particles

42‧‧‧Electrical particles

43‧‧‧Insulating particles

45‧‧‧Insulating particle body

46‧‧‧ layer

51‧‧‧Electrical Department

52‧‧‧Protrusion

81‧‧‧Connection structure

82‧‧‧1st connection object component

82a‧‧‧1st electrode

83‧‧‧2nd connection object component

83a‧‧‧2nd electrode

84‧‧‧Connecting Department

A‧‧‧ Conductive particles with insulating particles

Insulating particles in the circle of B1‧‧

Insulating particles on the circumference of B2‧‧‧

Fig. 1 is a view showing conductive particles with insulating particles according to a first embodiment of the present invention. Sectional view.

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

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

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

Fig. 5 is a schematic view for explaining a method of evaluating the coverage ratio.

The present invention will be described in detail below.

The conductive particles with insulating particles of the present invention include conductive particles having a conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the conductive particles. In the conductive particles with insulating particles of the present invention, the ratio (weight ratio (X/Y)) of the weight X of the entire insulating particles to the weight Y of the conductive particles is more than 0.03 and 0.25 or less.

By using the above-described configuration of the conductive particles with insulating particles of the present invention, in particular, by making the above ratio (weight (X/Y)) exceed 0.03, that is, by making the size of the insulating particles relatively large Further, the number of the insulating particles is relatively large, and when the bonded structure is obtained, excessive flow of the conductive particles with the insulating particles can be suppressed, and the conductive particles with the insulating particles can be efficiently disposed on the electrode. .

Further, in the present invention, the conductive particles with the insulating particles can be efficiently disposed on the electrode, and as a result, it is not necessary to arrange the conductive particles with the insulating particles in the space where the electrode is not formed (S). Since a large amount of conductive particles with insulating particles are used as a premise, the amount of conductive particles with insulating particles can be reduced.

Further, by using the above-described configuration of the conductive particles with insulating particles of the present invention, a conductive material comprising conductive particles with insulating particles and a binder resin is produced. In the case of the material, aggregation of the conductive particles with the insulating particles is less likely to occur, and the dispersibility of the conductive particles with the insulating particles is increased. Further, even if the aggregate of the conductive particles with the insulating particles is generated in the conductive material, the aggregate of the conductive particles with the insulating particles can be separated into the respective insulating properties by stirring the conductive material. Conductive particles of particles.

In addition, in recent years, with the miniaturization and high performance of the electronic device, the line (L) where the electrode is formed, that is, the electrode width and the space between the electrodes (S) where the electrode is not formed are narrowed. For example, it is necessary to electrically connect the fine electrodes having L/S of 20 μm or less/20 μm or less. In the case where the electrodes having a small L/S are electrically connected to each other, the prior conductive material has a problem that a large amount of conductive particles with insulating particles are easily disposed in the space (S), so that there is a problem that insulation defects are particularly likely to occur.

On the other hand, by using the conductive particles with insulating particles of the present invention, it becomes difficult to dispose the conductive particles in the space (S), and it is possible to effectively suppress the occurrence of insulation failure. In particular, since the insulating particles are relatively large in weight, the insulating property is effectively increased, and even when the electrodes having L/S of 20 μm or less/20 μm or less are electrically connected to each other, the insulation can be sufficiently improved. Sex.

The conductive particles with insulating particles according to the present invention are particularly particularly useful for the line (L) which is a portion where the electrodes (the first and second electrodes) are formed, that is, the electrode width and the electrode (the first and second electrodes) are not formed. When the L/S of the inter-electrode width of the space (S) is 30 μm or less/30 μm or less, the insulation reliability can be effectively improved, and when the L/S is 20 μm or less / 20 μm or less, the operation can be further improved. When the L/S is 17.5 μm or less / 17.5 μm or less, the insulation reliability can be further effectively improved, and it is particularly effective when the L/S is 15 μm or less / 15 μm or less. Improve the insulation reliability. The above L/S may be 50 μm or less / 50 μm or less.

Further, since the conductive particles with the insulating particles of the present invention can improve the conduction reliability, the line (L) which forms part of the electrode (first and second electrodes) is the most electrode width. The small value is preferably 30 μm or less, more preferably 20 μm or less, further preferably 17.5 μm or less, and particularly preferably 15 μm or less. The line (L), that is, the electrode width is preferably larger than the average particle diameter of the conductive particles with insulating particles, and more preferably 1.1 times or more the average particle diameter of the conductive particles, and more preferably 2 times or more. Better than 3 times. The above line (L), that is, the electrode width may be 50 μm or less.

Further, since the insulating particles with the insulating particles of the present invention can improve the insulation reliability, the space (S) where the electrodes (the first and second electrodes) are not formed, that is, the minimum value of the inter-electrode width is preferably 30 μm or less, more preferably 20 μm or less, further preferably 17.5 μm or less, and particularly preferably 15 μm or less. The space (S), that is, the width between the electrodes is preferably larger than the average particle diameter of the conductive particles containing the conductive particles of the insulating particles, and more preferably 1.1 times or more the average particle diameter of the conductive particles, and more preferably More than 2 times, especially preferably more than 3 times. The space (S), that is, the width between the electrodes may be 50 μm or less.

Since the insulating reliability of the insulating particles of the present invention is effectively increased by using the conductive particles with insulating particles of the present invention, the conductive particles with insulating particles of the present invention are preferably used for electrical connection between electrodes, and The space in which the portion of the electrode is formed, that is, the minimum width between the electrodes is 20 μm or less.

The above ratio (weight) from the viewpoint that the conductive particles with insulating particles are more efficiently disposed on the surface of the electrode and the dispersibility of the conductive particles with insulating particles in the conductive material is further improved. The ratio (X/Y) is preferably 0.031 or more. Moreover, the ratio (weight ratio (X/Y)) is preferably 0.2 or less, more preferably 0.15 or less, still more preferably 0.12 or less from the viewpoint of easily producing conductive particles with insulating particles.

Preferably, the insulating particles are organic particles or inorganic particles. In the case where the insulating particles are organic particles, the ratio (weight ratio (X/Y)) is preferably more than 0.03, and preferably 0.12 or less. When the insulating particles are inorganic particles, the ratio (weight ratio (X/Y)) is preferably 0.08 or more, and preferably 0.25 or less.

It is easy to produce conductive particles with insulating particles and attach insulating particles The conductive particles are more efficiently disposed on the surface of the electrode, and further, the insulating particles are preferably organic particles, from the viewpoint of further improving the dispersibility of the conductive particles with insulating particles in the conductive material. The above ratio (weight ratio (X/Y)) exceeds 0.03 and is 0.12 or less.

It is easy to produce conductive particles with insulating particles, and the conductive particles with insulating particles are more efficiently disposed on the surface of the electrode, thereby further improving the conductive particles of the insulating particles in the conductive material. From the viewpoint of dispersibility, the insulating particles are preferably inorganic particles, and the ratio (weight ratio (X/Y)) is 0.08 or more and 0.25 or less.

The conductive particles preferably have a substrate particle and a conductive portion disposed on a surface of the substrate particle from the viewpoint of reducing the cost, improving the flexibility of the conductive particle, and improving the conduction reliability between the electrodes. . The conductive portion is preferably a conductive layer. Moreover, by using the conductive particles having the substrate particles and the conductive portion disposed on the surface of the substrate particles, the ratio (weight ratio (X/Y)) and the following ratio (weight ratio (X) are easily obtained. /Z)) Control is the preferred range.

The insulating particles are integrated as a whole, and the conductive particles with insulating particles are more efficiently disposed on the surface of the electrode, and the dispersibility of the conductive particles with insulating particles in the conductive material is further improved. The ratio (weight ratio (X/Z)) of the weight X to the weight Z of the substrate particles exceeds 0.086, preferably 0.089 or more. The ratio (weight ratio (X/Z)) is preferably less than 0.600, more preferably 0.590 or less, still more preferably 0.560 or less from the viewpoint of easily producing conductive particles with insulating particles.

The above ratio (weight ratio (X/Y)) and the above ratio (weight ratio (X/Z)) can be made of insulating particles, conductive particles, and materials of the substrate particles, and further, by insulating particles, The conductive particles and the size of the substrate particles are appropriately adjusted.

The insulating particles are organic particles or inorganic particles. When the insulating particles are organic particles, the ratio (weight ratio (X/Z)) is preferably more than 0.086, and preferably. It is 0.350 or less. In the case where the insulating particles are inorganic particles, the ratio (weight ratio (X/Z)) is preferably 0.200 or more, and preferably 0.590 or less.

It is easy to produce conductive particles with insulating particles, and the conductive particles with insulating particles are more efficiently disposed on the surface of the electrode, thereby further improving the conductive particles of the insulating particles in the conductive material. From the viewpoint of dispersibility, the insulating particles are preferably organic particles, and the ratio (weight ratio (X/Z)) is more than 0.086 and 0.350 or less.

It is easy to produce conductive particles with insulating particles, and the conductive particles with insulating particles are more efficiently disposed on the surface of the electrode, thereby further improving the conductive particles of the insulating particles in the conductive material. From the viewpoint of dispersibility, the insulating particles are preferably inorganic particles, and the ratio (weight ratio (X/Z)) is 0.200 or more and less than 0.600, more preferably 0.200 or more and 0.590 or less.

The coverage of the entire surface area of the conductive particles, which is covered by the insulating particles, is preferably 30% or more, more preferably 50% or more, still more preferably 50% or more, and particularly preferably 60% or more. . When the coverage is at least the above lower limit, the adjacent conductive particles become more difficult to contact. The coverage ratio is preferably 95% or less, more preferably 90% or less, further preferably 80% or less, and particularly preferably 70% or less. When the coverage is less than or equal to the above upper limit, the insulating particles can be sufficiently removed even when heat and pressure are not required more than necessary when the electrodes are connected.

Specifically, the coverage ratio is obtained by the following method.

By observing 100 conductive particles containing insulating particles by observation with a scanning electron microscope (SEM, Scanning Electron Microscope), the coverage ratio X1 (%) of the conductive particles of the conductive particles with insulating particles was determined. (Also known as adhesion rate X1 (%)). The coverage ratio X1 is an area (projected area) of a portion of the entire surface area of the conductive particles covered by the insulating particles.

Specifically, as shown in Figure 5, using a scanning electron microscope (SEM) from a When the conductive particles A with insulating particles are observed in the direction, the insulating particles B1 present in the circle on the outer surface (outer peripheral edge) of the conductive portion of the conductive particles A with insulating particles are counted as one. The insulating particles B2 on the circumference of the outer surface (outer peripheral edge) of the conductive portion of the conductive particles A with insulating particles were counted to be 0.5. The coverage ratio is expressed by a ratio of a projected area of the insulating particles to a projected area of the conductive particles A with insulating particles.

That is, the above coverage ratio is represented by the following formula (1).

Coverage rate (%) = (((number of insulating particles in a circle) × 1 + (number of insulating particles on the circumference) × 0.5) × projected area of insulating particles) / (conductivity with insulating particles) Projection area of sexual particles)) × 100... Equation (1)

The conductive particles with insulating particles of the present invention are preferably dispersed in a binder resin and used as a conductive material. The conductive particles with insulating particles of the present invention are preferably used as a paste-like conductive paste. The above conductive material is preferably a conductive paste.

When the electrodes are connected between the electrodes by using the conductive particles with insulating particles, it is more difficult to cause a short circuit between the adjacent electrodes that are not connectable, and the connection between the electrodes above and below is sufficiently ensured. The conductive particles with insulating particles of the present invention are preferably used for a conductive paste having a viscosity at 25 ° C and 2.5 rpm of more than 100 Pa ‧ and less than 1000 Pa ‧ , and a viscosity of the conductive paste at 25 ° C and 2.5 rpm Good is over 100Pa‧s and is below 1000Pa‧s.

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

The coefficient of variation (CV) is expressed by the following formula.

CV value (%) = (ρ / Dn) × 100

ρ: standard deviation of the particle diameter of the conductive particles with insulating particles

Dn: average value of the particle diameter of the conductive particles with insulating particles

Further, the conductive particles containing the insulating particles are disposed on the surface of the conductive particles and are adsorbed to the polymer electrolyte via a polymer electrolyte that can be adsorbed to a polar group on the surface of the conductive particles. Conductive particles with insulating particles attached to insulating particles. The conductive particles with insulating particles are obtained by electrostatically adsorbing the insulating particles, for example, by electrostatically adsorbing the polymer electrolyte on at least a part of the surface of the conductive particles.

The present invention will be elucidated on the basis of the specific embodiments and examples of the present invention with reference to the drawings.

(Electroconductive particles with insulating particles)

Fig. 1 is a cross-sectional view showing conductive particles with insulating particles according to a first embodiment of the present invention.

The conductive particles 1 with insulating particles shown in FIG. 1 include conductive particles 2 and a plurality of insulating particles 3 disposed on the surface of the conductive particles 2. The insulating particles 3 are adhered to the surface of the conductive particles 2 . The insulating particles 3 are formed of a material having an insulating property. The insulating particles 3 are not coated particles. Instead of the insulating particles 3, the insulating particles 43 described below may be used.

The conductive particles 2 have the substrate particles 11 and the conductive portion 12 disposed on the surface of the substrate particles 11. The conductive portion 12 is a conductive layer. The conductive portion 12 covers the surface of the substrate particles 11. The conductive particles 2 are coated particles in which the surface of the substrate particles 11 is covered with the conductive portion 12 . The conductive particles 2 have a conductive portion 12 on the surface.

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

The conductive particles 21 with insulating particles shown in FIG. 2 include conductive particles 22 and a plurality of insulating particles 3 disposed on the surface of the conductive particles 22. The insulating particles 3 are adhered to the surface of the conductive particles 22. Instead of the insulating particles 3, the insulating particles 43 described below may be used.

The conductive particles 22 have the substrate particles 11 and the conductive portion 31 disposed on the surface of the substrate particles 11. The conductive portion 31 is a conductive layer. The conductive particles 22 have a plurality of core materials 32 on the surface of the substrate particles 11. The conductive portion 31 covers the substrate particles 11 and the core material 32. The conductive particles 22 have a plurality of protrusions 33 on the surface by coating the core portion 32 with the conductive portion 31. The surface of the conductive portion 31 is embossed by the core material 32, and a plurality of protrusions 33 are formed.

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

The conductive particles 41 with insulating particles shown in FIG. 3 include conductive particles 42 and a plurality of insulating particles 43 disposed on the surface of the conductive particles 42. Insulating particles 43 adhere to the surface of the conductive particles 42. Insulating particles 43 may be used instead of the insulating particles 43.

The conductive particles 42 have the substrate particles 11 and the conductive portion 51 disposed on the surface of the substrate particles 11. The conductive portion 51 is a conductive layer. The conductive particles 42 do not have a core material like the conductive particles 22 . The conductive portion 51 has a first portion and a second portion having a thickness thicker than the first portion. The conductive particles 42 have a plurality of protrusions 52 on the surface. The portion other than the plurality of protrusions 52 is the first portion of the conductive portion 51. The plurality of protrusions 52 are the second portions of the conductive portion 51 having a relatively large thickness. The insulating particles 43 are coated particles.

The insulating particles 43 have an insulating particle body 45 and a layer 46 covering the surface of the insulating particle body 45. The layer 46 is preferably formed of an organic compound, preferably a polymer compound.

The layer 46 covers the entire surface of the insulating particle body 5. Therefore, the layer 46 is disposed between the conductive particles 42 and the insulating particle body 45. The layer 46 may be provided so as to cover at least a part of the surface of the insulating particle body, or may not cover the entire surface of the insulating particle body. The layer 46 is preferably disposed between the conductive particles and the body of the insulating particles.

Conductive particles 1, 21, and 41 with insulating particles, insulating particles 3, 43 The ratio (weight ratio (X/Y)) of the total weight X to the weight Y of the conductive particles 2, 22, 42 exceeds 0.03 and is 0.25 or less. When such conductive particles 1, 21, and 41 with insulating particles are used for electrical connection between electrodes, the conductive particles 2, 22, and 42 can be efficiently disposed on the electrodes. Further, in the conductive material, aggregation of the conductive particles 1, 21, and 41 with insulating particles is less likely to occur, and the dispersibility of the conductive particles 1, 21, and 41 with insulating particles is increased.

The details of the conductive particles and the insulating particles will be described below.

[Electroconductive particles]

Conductive particles with insulating particles can be obtained by disposing the insulating particles on at least the surface of the conductive particles having a conductive portion on the surface. The conductive portion of the conductive particles is preferably a conductive layer.

The conductive particles may have at least a conductive portion on the surface. The conductive particles are preferably conductive particles having a substrate particle and a conductive portion disposed on the surface of the substrate particle.

The substrate particles are preferably substrate particles other than metal particles, more preferably resin particles, inorganic particles other than metals, or organic-inorganic hybrid particles.

The substrate particles are preferably resin particles formed of a resin. When the conductive particles having the insulating particles are connected between the electrodes, the conductive particles with the insulating particles are placed between the electrodes, and then the conductive particles with the insulating particles are compressed by pressure bonding. When the base material particles are resin particles, the conductive particles are easily deformed at the time of the pressure bonding, and the contact area between the conductive particles and the electrode is increased. Therefore, the conduction reliability between the electrodes becomes high.

As the resin for forming the above resin particles, various organic materials can be preferably used. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; and polymethacrylic acid; Acrylic resin such as methyl ester and polymethyl acrylate; polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde tree Grease, urea-formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polyfluorene, polyphenylene Ether, polyacetal, polyimine, polyamidoximine, polyetheretherketone, polyether oxime, divinylbenzene polymer, and divinylbenzene copolymer. Examples of the divinylbenzene-based copolymer and the like include a divinylbenzene-styrene copolymer and a divinylbenzene-(meth)acrylate copolymer. Since the hardness of the resin particles can be easily controlled to a preferred range, the resin for forming the resin particles is preferably one obtained by polymerizing one or two or more kinds of polymerizable monomers having an ethylenically unsaturated group. The polymer.

When the monomer having an ethylenically unsaturated group is polymerized to obtain the above resin particles, examples of the monomer having an ethylenically unsaturated group include a non-crosslinkable monomer and a crosslinkable monomer.

Examples of the non-crosslinkable monomer include a styrene monomer such as styrene or α-methylstyrene; and a carboxyl group-containing monomer such as (meth)acrylic acid, maleic acid or maleic anhydride; Methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, laurel (meth)acrylate Ester, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylate Alkyl (meth) acrylate such as ester; 2-hydroxyethyl (meth) acrylate, glyceryl (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate, etc. a (meth) acrylate containing an oxygen atom; a nitrile group-containing monomer such as (meth)acrylonitrile; a vinyl ether such as methyl vinyl ether, ethyl vinyl ether or propyl vinyl ether; Vinyl esters such as vinyl ester, vinyl butyrate, vinyl laurate, vinyl stearate; unsaturated hydrocarbons such as ethylene, propylene, isoprene, butadiene; and trifluoromethyl (meth)acrylate A halogen-containing monomer such as pentafluoroethyl (meth)acrylate, vinyl chloride, vinyl fluoride or chlorostyrene.

Examples of the crosslinkable monomer include tetramethylol methane tetra(meth)acrylate, tetramethylol methane tri(meth)acrylate, and tetramethylolmethane di(methyl)propyl. Ethyl ester, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth) acrylate, dipentaerythritol penta (meth) acrylate, tris(meth) acrylate, di(methyl) ) glyceryl acrylate, (poly)ethylene glycol di(meth) acrylate, (poly) propylene glycol di (meth) acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1, Polyfunctional (meth) acrylates such as 4-butanediol di(meth)acrylate; triallyl (iso) cyanurate, triallyl trimellitate, divinylbenzene, phthalic acid Diallyl ester, diallyl acrylamide, diallyl ether, γ-(meth) propylene methoxy propyl trimethoxy decane, trimethoxy decyl styrene, vinyl trimethoxy decane A monomer containing decane or the like.

The above resin particles can be obtained by polymerizing the above polymerizable monomer having an ethylenically unsaturated group by a known method. As such a method, for example, a method in which suspension polymerization is carried out in the presence of a radical polymerization initiator; and a method in which a non-crosslinked seed particle is used, and a monomer is swollen and polymerized by a radical polymerization initiator is used. .

In the case where the substrate particles are inorganic particles or organic-inorganic hybrid particles other than the metal, examples of the inorganic material for forming the substrate particles include ceria and carbon black. The particles formed of the cerium oxide are not particularly limited, and examples thereof include forming a crosslinked polymer particle by hydrolyzing a hydrazine compound having two or more hydrolyzable alkoxyalkylene groups, and then calcining it as necessary. And the particles obtained. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxyfluorene alkyl polymer and an acrylic resin.

The metal for forming the above-mentioned conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, palladium, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, ruthenium, osmium, iridium, osmium, cadmium, and tungsten. Molybdenum, niobium and these alloys. Further, examples of the metal include tin-doped indium oxide (ITO) and solder. Among them, since the connection resistance between the electrodes is further lowered, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is more preferable.

Further, in many cases, a hydroxyl group is present on the surface of the conductive portion due to oxidation. Generally In other words, a hydroxyl group is present on the surface of the conductive portion formed of nickel due to oxidation. Such a conductive portion having a hydroxyl group is easily chemically bonded to the insulating particles, and is chemically bonded to, for example, an insulating particle having a hydroxyl group.

The above conductive portion (conductive layer) may be formed of one layer. The conductive portion may also be formed of a plurality of layers. That is, the conductive portion may have a laminated structure of two or more layers. In the case where the conductive portion is formed of a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, a copper layer or an alloy layer containing tin and silver, more preferably a gold layer or a palladium layer, and particularly preferably a gold layer. . In the case where the outermost layer is such a preferred conductive portion, the connection resistance between the electrodes is further lowered. Further, when the outermost layer is a gold layer, the corrosion resistance is further increased.

The method of forming the conductive portion on the surface of the substrate particles is not particularly limited. Examples of the method of forming the conductive portion include a method of electroless plating, a method using electroplating, a method using physical vapor deposition, and a method of applying a metal powder or a slurry containing a metal powder and a binder to a substrate. The method of the surface of the particles, etc. Among them, since the formation of the conductive portion is relatively simple, it is preferable to use a method of electroless plating. Examples of the method using physical vapor deposition include vacuum deposition, ion plating, and ion sputtering.

As a method of forming a conductive portion on the surface of the substrate particles, a method using physical collision is also effective from the viewpoint of improving productivity. As a method of forming by physical collision, for example, there is a method of coating using Theta Composer (manufactured by Deshou Works Co., Ltd.).

The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, and is preferably 100 μm or less, more preferably 20 μm or less, further preferably 5 μm or less, and particularly preferably 3 μm or less. When the average particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, when the conductive particles with insulating particles are connected between the electrodes, the contact area between the conductive particles and the electrode is sufficiently increased. When the conductive portion is formed, it becomes difficult to form agglomerated conductive particles. Moreover, the interval between the electrodes connected via the conductive particles does not become excessively large, and the conductive portion becomes difficult to peel off from the surface of the substrate particles.

The "average particle diameter" of the above conductive particles means a number average particle diameter. The average particle diameter of the conductive particles is determined by observing an arbitrary 50 conductive particles by an electron microscope or an optical microscope and calculating an average value.

The thickness of the conductive portion (conductive layer) is preferably 0.005 μm or more, more preferably 0.01 μm or more, and is preferably 1 μm or less, and more preferably 0.3 μm or less. When the thickness of the conductive portion is not less than the above lower limit and not more than the above upper limit, sufficient conductivity is obtained, and the conductive particles are not excessively hard, and the conductive particles are sufficiently deformed at the time of connection between the electrodes.

When the conductive portion (conductive layer) is formed of a plurality of layers, the thickness of the outermost conductive portion, particularly the thickness of the gold layer in the case where the outermost layer is a gold layer, is preferably 0.001 μm or more, more preferably 0.01 μm. The above is preferably 0.5 μm or less, more preferably 0.1 μm or less. When the thickness of the outermost conductive portion is not less than the above lower limit and not more than the above upper limit, the coating of the outermost conductive portion can be uniformly performed, the corrosion resistance is sufficiently increased, and the connection resistance between the electrodes is sufficiently lowered.

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

Preferably, the conductive particles have a plurality of protrusions on the surface of the conductivity. Preferably, the conductive portion has a plurality of protrusions on the surface (outer surface). In many cases, an oxide film is formed on the surface of the electrode to which the conductive particles of the insulating particles are attached. Further, in many cases, an oxide film is formed on the surface of the conductive portion of the conductive particles. After the conductive particles having the insulating particles are disposed between the electrodes by using the conductive particles having the protrusions, the oxide film is effectively removed by the protrusions by pressure bonding. Therefore, the electrode and the conductive particles are more reliably contacted, and the connection resistance between the electrodes is lowered. Further, the insulating particles between the conductive particles and the electrode can be effectively excluded by the protrusion of the conductive particles. Therefore, the conduction reliability between the electrodes is further increased.

As a method of forming a protrusion on the surface of the conductive particle, a core substance can be cited. After adhering to the surface of the substrate particles, a method of forming a conductive portion by electroless plating; forming a conductive portion on the surface of the substrate particles by electroless plating, and then attaching the core material, thereby performing electroless plating A method of forming a conductive portion; and a method of adding a core material to an electroless plating solution in a middle of forming a conductive portion by electroless plating on a surface of the substrate particle. Further, in order to form the protrusions, the core material may not necessarily be used. When the conductive portion is formed by electroless plating or the like, the protrusion may be formed by partially varying the thickness of the conductive portion.

The conductive particles may have a first conductive portion on the surface of the substrate particle and a second conductive portion on the surface of the first conductive portion. In this case, the core substance may be attached to the surface of the first conductive portion. The core material is preferably covered by the second conductive portion. The thickness of the first conductive portion is preferably 0.05 μm or more, and preferably 0.5 μm or less. It is preferable that the conductive particles form a second conductive portion on the surface of the substrate particles, and then the core material adheres to the surface of the first conductive portion, and then forms a second surface on the surface of the first conductive portion and the core material. Obtained from the conductive portion.

Examples of the material constituting the core material include a conductive material and a non-conductive material. Examples of the conductive material include a metal, a metal oxide, a conductive non-metal such as graphite, and a conductive polymer. Examples of the conductive polymer include polyacetylene and the like. Examples of the non-conductive material include cerium oxide, aluminum oxide, and zirconium oxide. Among them, since it is possible to improve conductivity, it is preferably a metal. The core material is preferably a metal particle.

Examples of the metal include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, ruthenium, osmium, iridium, and cadmium, and tin-lead. An alloy containing two or more kinds of metals such as an alloy, a tin-copper alloy, a tin-silver alloy, a tin-lead-silver alloy, and a tungsten carbide. Among them, nickel, copper, silver or gold is preferred. The metal constituting the core material may be the same as or different from the metal constituting the conductive portion.

The shape of the core material is not particularly limited. The shape of the core material is preferably a block shape. Examples of the core material include a particulate block, agglomerates in which a plurality of fine particles are aggregated, and an amorphous block.

[insulating particles]

The insulating particles are insulating particles. The insulating particles are preferably smaller than the conductive particles. When the conductive particles with insulating particles are used to connect the electrodes, the short-circuit between the adjacent electrodes can be prevented by the insulating particles. Specifically, when a plurality of conductive particles with insulating particles are in contact with each other, insulating particles are present between the conductive particles of the plurality of conductive particles with insulating particles, so that it can be prevented between the electrodes adjacent to each other in the lateral direction. Short circuit between electrodes that are not upper and lower. Further, in the connection between the electrodes, the insulating particles between the conductive portion and the electrode can be easily removed by pressurizing the conductive particles with the insulating particles by the two electrodes. When the protrusion is provided on the surface of the conductive portion, the insulating particles between the conductive portion and the electrode can be easily excluded. Further, since the protruding portion makes contact with the electrode easy, the connection reliability is improved.

Examples of the material constituting the insulating particles include an insulating resin and an insulating inorganic material. The resin which is exemplified as the resin for forming the resin particles which can be used as the substrate particles is exemplified as the insulating resin. The above-mentioned inorganic substance exemplified as the inorganic substance for forming the inorganic particles which can be used as the substrate particles can be mentioned as the insulating inorganic material.

The insulating particles are preferably organic particles or inorganic particles. The above organic particles are formed using an organic compound (for example, an insulating resin). The above inorganic particles are formed using an inorganic compound.

Specific examples of the insulating resin as the material of the insulating particles include polyolefins, (meth)acrylate polymers, (meth)acrylate copolymers, block polymers, thermoplastic resins, and thermoplastic resins. A crosslinked product of a resin, a thermosetting resin, a water-soluble resin, or the like.

Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, and Ethylene-acrylate copolymer and the like. Examples of the (meth) acrylate polymer include poly(methyl) acrylate, poly(ethyl) acrylate, and poly(meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylate copolymer, styrene-butadiene (styrene-butadiene) type styrene-butadiene block copolymer, and SBS (styrene). a -butadiene-styrene, styrene-butadiene-styrene type styrene-butadiene block copolymer, and the like, and the like. Examples of the thermoplastic resin include a vinyl polymer and a vinyl copolymer. Examples of the thermosetting resin include an epoxy resin, a phenol resin, and a melamine resin. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polypropylene decylamine, polyvinylpyrrolidone, polyethylene oxide, and methyl cellulose. Among them, a water-soluble resin is preferred, and polyvinyl alcohol is more preferred.

In the conductive particles with insulating particles of the present invention, it is preferable that the insulating particles have an insulating particle body and a layer covering at least a part of a surface of the insulating particle body. Thereby, the insulating particles become more difficult to be detached from the surface of the conductive particles by kneading at the time of producing the conductive material. Further, when a plurality of conductive particles with insulating particles are in contact with each other, the insulating particles are less likely to be detached from the surface of the conductive particles. In order to effectively suppress unintentional detachment of the insulating particles, the insulating particles or the material of the insulating particles are preferably inorganic compounds, and the insulating particles or the insulating particles are preferably inorganic particles. In order to effectively suppress unintentional detachment of the insulating particles, the layer covering at least a part of the surface of the insulating particle body is preferably formed of an organic compound, and the organic compound is preferably a polymer compound. Further, the surface of the inorganic particles covered with a layer formed of an organic compound is referred to as inorganic particles in the present specification. The surface of the organic particle is referred to as an organic particle in the present specification by a particle covered with a layer formed of an organic compound. The inorganic particles are mostly (for example, 80% by weight or more) particles formed of an inorganic compound. Most of the above organic particles (for example, 80% by weight or more) of particles formed of an organic compound.

The conductive particles with the insulating particles are preferably obtained by the following steps: A polymer compound or a compound which is a polymer compound is used to cover at least a part of the surface of the insulating particle body, and a layer formed of a polymer compound is formed to obtain insulating particles; and the insulating particles are attached to the insulating particles. Conductive particles with insulating particles are obtained at least on the surface of the conductive particles having a conductive portion on the surface.

The insulating particles or the insulating particles are preferably inorganic particles, and are preferably cerium oxide particles, from the viewpoint of further improving the detachability of the insulating particles during thermocompression bonding. Examples of the inorganic particles include white sand particles, hydroxyapatite particles, magnesium oxide particles, zirconia particles, alumina particles, cerium carbide particles, cerium nitride particles, aluminum nitride particles, and cerium oxide particles. Examples of the cerium oxide particles include pulverized cerium oxide and spherical cerium oxide, and spherical cerium oxide is preferably used. Further, the cerium oxide particles preferably have a functional group capable of chemical bonding such as a carboxyl group or a hydroxyl group on the surface, and more preferably have a hydroxyl group. The inorganic particles are relatively hard, especially the cerium oxide particles are relatively hard. When the conductive particles containing the insulating particles as the insulating particles are directly added to the binder resin and kneaded, the insulating particles are hard, so that the insulating particles are easy. The tendency to detach from the surface of the conductive particles. In the case where the insulating particles have the above-described layer formed of the polymer compound, even if the hard insulating particles are used, the insulating particles which are hard at the time of the kneading can be prevented from being detached.

The layer formed of the organic compound and the layer formed of the polymer compound described above function as a soft layer, for example. The polymer compound which is a layer formed of the polymer compound or a compound which becomes the polymer compound by polymerization or the like is preferably a compound having a polymerizable reactive functional group. The polymerizable reactive functional group is preferably an unsaturated double bond. For example, a compound having an unsaturated double bond (a compound which is a polymer compound) can be polymerized on the surface of the insulating particle body, and a reactive function of the polymer compound and the surface of the insulating particle body can be used. The base reacts. Examples of the polymer compound include a compound having a (meth)acryl fluorenyl group, a compound having an epoxy group, and a compound having a vinyl group. Conductive particles dispersed with insulating particles When the insulating particles are detached from the surface of the conductive particles, the polymer compound or the compound which is the polymer compound preferably has a selected from the group consisting of (meth) acrylonitrile groups and glycidyl groups. At least one reactive functional group of the group consisting of vinyl groups. In particular, the polymer compound or the compound which is the polymer compound preferably has a (meth) acrylonitrile group from the viewpoint of further suppressing the detachment of the insulating particles.

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

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

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

The average particle diameter of the insulating particles can be appropriately selected depending on the particle diameter of the conductive particles and the use of the conductive particles with the insulating particles. The average particle diameter of the insulating particles is preferably 0.005 μm or more, more preferably 0.01 μm or more, further preferably 5 μm or less, more preferably 2.5 μm or less, further preferably 1 μm or less, and particularly preferably 0.5 μm or less. When the average particle diameter of the insulating particles is at least the above lower limit, when the conductive particles with the insulating particles are dispersed in the binder resin, the conductive particles of the plurality of conductive particles with insulating particles become difficult to contact each other. . When the average particle diameter of the insulating particles is not more than the above upper limit, it is not necessary to excessively increase the pressure during the connection between the electrodes, and it is not necessary to heat to a high temperature to exclude insulating particles between the electrode and the conductive particles.

The "average particle diameter" of the above insulating particles means a number average particle diameter. The average particle diameter of the insulating particles is determined using a particle size distribution measuring device or the like.

The average particle diameter of the insulating particles is preferably 1/2 or less of the particle diameter of the conductive particles, more preferably 1/3 or less, further preferably 1/4 or less, and particularly preferably 1/5 or less. The particle diameter of the insulating particles is preferably 1/1000 or more, more preferably 1/10 or more, of the particle diameter of the conductive particles. More preferably, it is more than 1/10. When the average particle diameter of the insulating particles is 1/5 or less of the particle diameter of the conductive particles, for example, when the conductive particles with insulating particles are produced, the insulating particles are more efficiently adhered to the surface of the conductive particles. .

The average particle diameter of the insulating particles is preferably 0.5 times or more the thickness of the conductive portion (conductive layer) of the conductive particles, and more preferably 1 time or more. The average particle diameter of the insulating particles is preferably 20 times or less the thickness of the conductive portion (conductive layer) of the conductive particles, and more preferably 10 times or less. When the average particle diameter of the insulating particles and the thickness of the conductive portion satisfy such a preferable relationship, the conductive particles of the plurality of conductive particles with insulating particles become difficult to contact each other, and the conductive portion and the electrode can be easily removed. Insulating particles between.

The average particle diameter of the insulating particles is preferably larger than the average particle diameter of the core material, and more preferably 1.1 times or more. The average particle diameter of the insulating particles is preferably 20 times or less the average particle diameter of the core material, and more preferably 10 times or less. When the average particle diameter of the insulating particles and the average particle diameter of the core material satisfy such a preferable relationship, the conductive particles of the plurality of conductive particles with insulating particles become difficult to contact each other, and the conductive can be easily excluded. Insulating particles between the part and the electrode.

The "average particle diameter" of the above core material means a number average particle diameter. The average particle diameter of the core material is determined by using a particle size distribution measuring device or the like.

The average particle diameter of the insulating particles is preferably larger than the average height of the protrusions, and more preferably 1.1 times or more. The average particle diameter of the insulating particles is preferably 20 times or less, more preferably 10 times or less the height of the protrusions. When the average particle diameter of the insulating particles and the height of the protrusions satisfy such a preferable relationship, the conductive particles of the plurality of conductive particles with insulating particles become difficult to contact each other, and the conductive portion and the electrode can be easily removed. Insulating particles between.

The average height of the protrusions is the average of the heights of the plurality of protrusions.

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

Two or more kinds of insulating particles having different particle diameters can also be used. In this case, since the smaller insulating particles can be present between the larger insulating particles on the surface of the conductive particles, the exposed area of the conductive particles can be made small. Therefore, even if a plurality of conductive particles with insulating particles are in contact, since adjacent conductive particles are hard to contact, short circuits between adjacent electrodes can be suppressed. The average particle diameter of the smaller insulating particles is preferably 1/2 or less of the average particle diameter of the larger insulating particles. The number of the smaller insulating particles is preferably 1/4 or less of the number of the larger insulating particles.

(conductive material)

The conductive material of the present invention comprises the above-mentioned conductive particles with insulating particles and a binder resin. When the conductive particles with the insulating particles are used, the insulating particles are less likely to be detached from the surface of the conductive particles when the conductive particles with the insulating particles are dispersed in the binder resin. The conductive material of the present invention is preferably an anisotropic conductive material.

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

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

The conductive material may contain, for example, a filler, a bulking agent, a softening agent, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, and the like in addition to the conductive particles with the insulating particles and the binder resin. Various additives such as oxidizing agents, heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, and flame retardants.

The method of dispersing the conductive particles containing the insulating particles in the binder resin can be a conventionally known dispersion method, and is not particularly limited. As a method of dispersing the conductive particles containing the insulating particles in the binder resin, for example, a method in which the conductive particles having the insulating particles are added to the binder resin is used, and then a planetary mixer is used. a method of dispersing and dispersing the conductive particles, and uniformly dispersing the conductive particles of the insulating particles in water or an organic solvent, and then adding them to the binder resin, and using a planetary mixer or the like. And a method of mixing and dispersing the above-mentioned binder resin with water or an organic solvent, and then adding the conductive particles with the insulating particles and kneading them by a planetary mixer or the like .

The above conductive material can be used as a conductive paste, a conductive film, or the like. The above conductive paste may be a conductive ink or a conductive adhesive. Further, the conductive film includes a conductive sheet. In the case where the conductive material containing the conductive particles with insulating particles is a conductive film, the conductive film containing the conductive particles with insulating particles may be a film containing conductive particles with insulating particles. However, as described above, the conductive material of the present invention is preferably in the form of a paste, preferably a conductive paste. The paste contains liquid. The above conductive paste is preferably an anisotropic conductive paste. The above conductive film is preferably an anisotropic conductive film.

The content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, and particularly preferably 70% by weight or more, and preferably 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles with insulating particles are efficiently disposed between the electrodes, and the connection reliability of the connecting member connected by the conductive material is further changed. high.

The content of the conductive particles of the insulating particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and preferably 40% by weight or less, more preferably 20% by weight, based on 100% by weight of the conductive material. Hereinafter, it is more preferably 10% by weight or less. When the content of the conductive particles with the insulating particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes is further increased.

(connection structure)

The connection structure member can be connected by using the conductive material containing the conductive particles with insulating particles and the binder resin of the present invention to obtain a connection structure.

The connection structure includes a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, and a connection portion connecting the first connection target member and the second connection target member. . The connection portion is formed of a conductive material containing the conductive particles with the insulating particles and the binder resin. The first electrode and the second electrode are electrically connected by the conductive particles of the conductive particles with insulating particles.

In the front cross-sectional view of Fig. 4, a connection structure using conductive particles with insulating particles according to the first embodiment of the present invention is schematically shown.

The connection structure 81 shown in FIG. 4 includes a first connection target member 82, a second connection target member 83, and a connection portion 84 that connects the first and second connection object members 82 and 83. The connection portion 84 is formed of a conductive material containing the conductive particles 1 with insulating particles. The connecting portion 84 is preferably formed by curing a conductive material containing a plurality of conductive particles 1 with insulating particles. In addition, in FIG. 4, the electroconductive particle 1 with an insulating particle is shown in the figure for convenience. It is also possible to use conductive particles 21, 41 or the like with insulating particles instead of Conductive particles 1 with insulating particles.

The first connection target member 82 has a plurality of first electrodes 82a on the front surface (upper surface). The second connection target member 83 has a plurality of second electrodes 83a on the front surface (lower surface). The first electrode 82a and the second electrode 83a are electrically connected by one or a plurality of conductive particles 2 of the conductive particles 1 with insulating particles. Therefore, the first and second connection target members 82 and 83 are electrically connected by the conductive particles 2 of the conductive particles 1 with insulating particles.

The method for producing the above-described connection structure is not particularly limited. An example of the method of manufacturing the connection structure is a method in which the conductive material is placed between the first connection target member and the second connection target member, and the laminate is heated and pressurized. The pressure of the above pressurization is about 9.8 × 10 ⁴ to 4.9 × 10 ⁶ Pa. The heating temperature is about 120 to 220 °C.

When the laminate is heated and pressurized, the insulating particles 3 existing between the conductive particles 2 and the first and second electrodes 82a and 83a can be eliminated. For example, during the heating and pressurization, the insulating particles 3 existing between the conductive particles 2 and the first and second electrodes 82a and 83a are melted or deformed, and the surface of the conductive particles 2 is partially exposed. In addition, when the heating and pressurization are performed, a large amount of force is applied, and therefore some of the insulating particles 3 are peeled off from the surface of the conductive particles 2 to partially expose the surface of the conductive particles 2. The portion exposed by the surface of the conductive particles 2 is in contact with the first and second electrodes 82a and 83a, and the first and second electrodes 82a and 83a can be electrically connected via the conductive particles 2.

Specific examples of the connection target member include electronic components such as a semiconductor wafer, a capacitor, and a diode, and electronic components such as a printed circuit board, a flexible printed circuit board, a glass epoxy board, and a circuit board such as a glass substrate. The conductive material is preferably a conductive material for connecting electronic components. The above conductive material is preferably a conductive material for circuit connection. The conductive material is preferably a paste-like conductive paste which is applied to the member to be joined in a paste state.

Reliable insulation by using the conductive particles with insulating particles of the present invention In terms of the effective increase in height, the space where the portion of the first electrode is not formed, that is, the minimum value of the width between the electrodes and the space where the second electrode is not formed, that is, the minimum width between the electrodes is preferably 20 μm or less.

The conductive particles with insulating particles of the present invention are particularly preferably used for forming a COG of a glass substrate and a semiconductor wafer as a connection member, and a glass epoxy substrate and a flexible printed circuit (FPC). The FOB of the connection target member or the FOG which uses the glass substrate and the flexible printed circuit board (FPC) as the connection target member can be used for COG or FOG, and can also be used for FOB or FOG. The conductive particles with insulating particles of the present invention can be used for COG, FOB, and FOG. In the connection structure of the present invention, it is preferable that the first and second connection target members are a glass substrate and a semiconductor wafer, or a glass epoxy substrate and a flexible printed substrate, or a glass substrate and a flexible printed substrate. The first and second connection target members may be a glass substrate or a semiconductor wafer, or may be a glass epoxy substrate or a flexible printed substrate, or may be a glass substrate or a flexible printed substrate.

Preferably, the semiconductor wafer used for the COG in which the glass substrate and the semiconductor wafer are connected to each other is provided with bumps. The bump size is preferably an electrode area of 1000 μm ² or more and 10000 μm ² or less. The electrode space of the semiconductor wafer provided with the bumps (electrodes) is preferably 30 μm or less, more preferably 20 μm or less, still more preferably 10 μm or less. The conductive particles with insulating particles of the present invention can be preferably used for such COG use. In the FPC used for the FOG in which the glass substrate and the flexible printed circuit board are connected to each other, the electrode space is preferably 30 μm or less, and more preferably 20 μm or less.

Examples of the electrode provided in the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a molybdenum electrode, and a tungsten electrode. In the case where the connection target member is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode or a copper electrode. In the case where the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode or a tungsten electrode. Furthermore, in the above electricity In the case of an extremely aluminum electrode, it may be an electrode formed only of aluminum, or an electrode having an aluminum layer on the surface layer of the metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al, Ga, and the like.

The present invention will be specifically described below by way of examples and comparative examples. The invention is not limited to the following examples.

(conductive particles)

The following conductive particles A to G were prepared. Further, the conductive particles having a plurality of protrusions on the surface of the conductive layer are formed by disposing a plurality of nickel fine particles between the divinylbenzene resin particles and the nickel plating layer.

Conductive particles A having a nickel-plated layer (conductive layer, thickness: 0.11 μm) were formed on the surface of the divinylbenzene resin particles (average particle diameter: 2.78 μm) (the surface of the conductive layer did not have protrusions, and the average particle diameter was 3.00 μm)

Conductive particles B having a nickel-plated layer (conductive layer, thickness: 0.125 μm) formed on the surface of the divinylbenzene resin particles (average particle diameter: 2.78 μm) (having no protrusion on the surface of the conductive layer, an average particle diameter of 3.03 μm)

A nickel plating layer (conductive layer, thickness 0.08 μm) is formed on the surface of the divinylbenzene resin particles (average particle diameter of 2.78 μm), and a gold layer (conductive layer, thickness 0.03 μm) is formed on the surface of the nickel plating layer. Conductive particle C (haves no protrusion on the surface of the conductive layer, average particle diameter 3.00 μm)

Conductive particles D having a nickel-plated layer (conductive layer, thickness: 0.11 μm) formed on the surface of the divinylbenzene resin particles (average particle diameter: 2.78 μm) (having a plurality of protrusions on the surface of the conductive layer (average height: 0.1 μm) , average particle size 3.00μm)

Conductive particles E having a nickel-plated layer (conductive layer, thickness: 0.125 μm) formed on the surface of the divinylbenzene resin particles (average particle diameter: 2.78 μm) (having a plurality of protrusions on the surface of the conductive layer (average height: 0.1 μm) , average particle size 3.03μm)

A nickel plating layer (conductive layer, thickness 0.08 μm) is formed on the surface of the divinylbenzene resin particles (average particle diameter of 2.78 μm), and a gold layer (conductive layer, thickness 0.03 μm) is formed on the surface of the nickel plating layer. Conductive particles F (having a plurality of protrusions on the surface of the conductive layer (average height 0.2 μm), average particle diameter 3.00 μm)

Conductive particles G having a nickel-plated layer (conductive layer, thickness: 0.11 μm) formed on the surface of the divinylbenzene resin particles (average particle diameter: 2.28 μm) (having a plurality of protrusions on the surface of the conductive layer (average height: 0.1 μm) , average particle size 2.50μm)

(Step of producing insulating particles)

The following insulating particles a to c were produced.

Using a monomer composition comprising methyl methacrylate, ethylene glycol dimethacrylate, acid phosphorus oxypolyethylene glycol methacrylate, and a polymerization initiator, soap-free polymerization is obtained. Insulating particles a (average particle diameter: 250 nm), insulating particles b (average particle diameter: 180 nm), and insulating particles c (average particle diameter: 350 nm).

The following insulating particles d~f were prepared.

Insulating particles d (average particle diameter: 400 nm) of cerium oxide particles produced by a sol-gel method

Insulating particles e (average particle diameter: 150 nm) of cerium oxide particles produced by a sol-gel method

Insulating particles f (average particle diameter: 500 nm) of cerium oxide particles produced by a sol-gel method

The obtained insulating particles a to f were each dispersed in distilled water to obtain a 10% by weight dispersion of the insulating particles a to f.

(Example 1)

The conductive particles A having no protrusions on the surface of the conductive portion and the 10% by weight dispersion liquid of the insulating particles a were prepared.

After dispersing the conductive particles A in 50 parts by weight in 300 mL of distilled water, the insulation was dropped. A 10% by weight dispersion of the particles a was stirred at 50 ° C for 8 hours to obtain a stirring solution. After the obtained stirring liquid was filtered, it was washed with methanol, and vacuum-dried at 50 ° C for 7 hours to obtain conductive particles with insulating particles. Further, in the first embodiment, the following examples, and the comparative examples described below, the coverage ratio was adjusted by the amount of the dispersion of 10% by weight of the insulating particles a to f.

The above-described coverage ratio X1, the above ratio (weight ratio (X/Y)), and the above ratio (weight ratio (X/Z)) of the conductive particles of the obtained insulating particles are shown in Table 1 below.

(Examples 2 to 7 and Comparative Examples 1 and 2)

Insulation was obtained in the same manner as in Example 1 except that the types of the conductive particles and the insulating particles were changed as shown in the following Table 1, and the above-described coverage ratio X1 was set as shown in Table 1 below. Conductive particles of particles.

(Example 8)

The conductive particles D having protrusions and the 10% by weight dispersion liquid of the insulating particles a were prepared on the surface of the conductive portion.

After dispersing the conductive particles D50 parts by weight in 300 mL of distilled water, a dispersion of 10% by weight of the insulating particles a was dropped, and the mixture was stirred at 50 ° C for 8 hours to obtain a stirring liquid. After the obtained stirring liquid was filtered, it was washed with methanol, and vacuum-dried at 50 ° C for 7 hours to obtain conductive particles with insulating particles.

The above-described coverage ratio X1, the above ratio (weight ratio (X/Y)), and the above ratio (weight ratio (X/Z)) of the conductive particles of the obtained insulating particles are shown in Table 2 below.

(Examples 9 to 15 and Comparative Examples 3 and 4)

Insulation was obtained in the same manner as in Example 8 except that the types of the conductive particles and the insulating particles were changed as shown in the following Table 2, and the above-described coverage ratio X1 was set as shown in Table 2 below. Conductive particles of particles.

The weight ratios shown in the following Tables 1 and 2 are measured values. However, the weight ratio can also be obtained by the following calculation method of the weight ratio. In the examples and comparative examples of the present case, the measured values and the The weight below is consistent with the value obtained by the calculation method.

(weight ratio calculation method)

The weight of one conductive particle is calculated from the specific gravity, the thickness and the volume of the conductive portion. In addition, the number of insulating particles of each conductive particle with insulating particles is calculated based on the coverage ratio (coating density), and the number of insulating particles of each conductive particle with insulating particles is multiplied by insulating particles. The specific gravity is the weight of the entire insulating particles of the conductive particles with insulating particles. Calculate each weight ratio.

(Evaluation) (1) Production of anisotropic conductive paste

20 parts by weight of an epoxy compound ("EP-3300P" manufactured by Nagase ChemteX Co., Ltd.) and 15 parts by weight of an epoxy compound ("EPICLON HP-4032D" manufactured by DIC Corporation) as a thermosetting compound 10 parts by weight of an amine-added product of imidazole ("PN-F" manufactured by Ajinomoto Fine-Techno Co., Ltd.) as a thermosetting agent, and 1 part by weight of 2-ethyl-4-methylimidazole as a curing accelerator. And 20 parts by weight of alumina (average particle diameter: 0.5 μm) as a filler, and further, after adding the conductive particles with insulating particles of the examples and the comparative examples, the content of the compound in 100% by weight of the preparation is 10% by weight. The mixture was stirred at 2000 rpm for 5 minutes using a planetary mixer, whereby an anisotropic conductive paste was obtained.

(2) Production of the first connection structure (L/S = 20 μm / 20 μm)

A glass substrate having an Al-Ti 4% electrode pattern (Al-Ti 4% electrode thickness: 1 μm) having an L/S of 20 μm/20 μm on the upper surface was prepared. Further, a semiconductor wafer having a gold electrode pattern (gold electrode thickness: 20 μm) having an L/S of 20 μm/20 μm was prepared on the lower surface.

The anisotropic conductive paste immediately after the application was applied to the upper surface of the glass substrate so as to have a thickness of 20 μm to form an anisotropic conductive material layer. Then, the semiconductor wafer is laminated on the upper surface of the anisotropic conductive material layer with the electrodes facing each other. Thereafter, the head is adjusted in such a manner that the temperature of the anisotropic conductive material layer becomes 185 ° C. At the temperature, a pressure heating head was placed on the upper surface of the semiconductor wafer, and a pressure of 3.0 MPa was applied to cure the anisotropic conductive material layer at 185 ° C to obtain a first connection structure.

(3) Production of the second connection structure (L/S = 30 μm / 30 μm)

A glass substrate having an Al-Ti 4% electrode pattern (Al-Ti 4% electrode thickness: 1 μm) having an L/S of 30 μm/30 μm was prepared on the upper surface. Further, a semiconductor wafer having a gold electrode pattern (gold electrode thickness: 20 μm) having an L/S of 30 μm/30 μm was prepared on the lower surface.

The second connection structure was obtained in the same manner as the production of the first connection structure except that the glass substrate and the semiconductor wafer having different L/S were used.

(4) Production of the third connection structure (L/S = 50 μm / 50 μm)

A glass substrate having an Al-Ti 4% electrode pattern (Al-Ti 4% electrode thickness: 1 μm) having an L/S of 50 μm/50 μm was prepared on the upper surface. Further, a semiconductor wafer having a gold electrode pattern (gold electrode thickness: 20 μm) having an L/S of 50 μm/50 μm was prepared on the lower surface.

The third connection structure was obtained in the same manner as the production of the first connection structure, except that the glass substrate and the semiconductor wafer having different L/S were used.

(5) Viscosity

The viscosity of the obtained conductive material (anisotropic conductive paste) was measured at 25 ° C and 2.5 rpm using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.). The viscosity was determined on the basis of the following criteria.

[Standard of viscosity determination]

A: more than 100Pa‧s and less than 1000Pa‧s

B: does not meet A

(6) Arrangement accuracy of conductive particles on the electrodes

With respect to the obtained first, second, and third connection structures, the conductive particles contained in the connection portion formed of the conductive material were confirmed. The ratio (%) of the number of the conductive particles disposed on the electrode and the number of the conductive particles disposed between the electrodes was evaluated. The arrangement accuracy of the conductive particles on the electrodes was determined based on the following criteria.

[Criteria for Judging the Arrangement Accuracy of Conductive Particles on Electrodes]

○○: The ratio of the number of conductive particles disposed on the electrode is 70% or more

○: The ratio of the number of conductive particles disposed on the electrode is 60% or more and less than 70%

△: The ratio of the number of conductive particles disposed on the electrode is 50% or more and less than 60%

×: the ratio of the number of conductive particles disposed on the electrode is less than 50%

(7) Continuity reliability between upper and lower electrodes

With respect to the obtained first, second, and third connection structures (n = 15), the connection resistance between the upper and lower electrodes was measured by a four-terminal method. Calculate the average value of the connection resistance. Further, according to the relationship of voltage=current×resistance, the connection resistance can be obtained by measuring the voltage at which a fixed current flows. The conduction reliability was determined based on the following criteria.

[Determination of Conductivity Reliability]

○○: The average value of the connection resistance is 2.0 Ω or less

○: The average value of the connection resistance exceeds 2.0 Ω and is 5.0 Ω or less.

△: The average value of the connection resistance exceeds 5.0 Ω and is 10.0 Ω or less.

×: The average value of the connection resistance exceeds 10.0 Ω

(8) Insulation reliability between adjacent electrodes

The obtained first, second, and third connection structures (n=15) were placed in an environment of 85° C. and 85% for 100 hours, and then the adjacent electrodes were in an insulated state or a conductive state at 25 points. . The insulation reliability was determined on the basis of the following criteria.

[Determination of insulation reliability]

○○: 25 places between the electrodes in the insulated state

○: There are 20 or more electrodes in the insulated state and less than 25 places.

△: 15 or more electrodes and less than 20 places in the insulated state

×: less than 15 between the electrodes in the insulated state

The results are shown in Tables 1 and 2 below.

Further, in the third and tenth embodiments, the results of the evaluation of the conduction evaluation of the first, second, and third connection structures were the same, but the value of the connection resistance of the tenth embodiment was lower than that of the third embodiment. In the fifth and twelfth embodiments, the results of the evaluation of the conduction evaluation of the first, second, and third connection structures were the same, but the value of the connection resistance of the embodiment 12 was lower than that of the fifth embodiment. In the seventh embodiment and the fourteenth embodiment, the determination results of the results of the conduction evaluation of the first, second, and third connection structures were the same, but the value of the connection resistance of the fourteenth embodiment was lower than that of the seventh embodiment.

1‧‧‧ Conductive particles with insulating particles

2‧‧‧Electrical particles

3‧‧‧Insulating particles

11‧‧‧Substrate particles

12‧‧‧Electrical Department

Claims (14)

A conductive particle containing insulating particles, comprising: at least a conductive particle having a conductive portion on a surface thereof; and a plurality of insulating particles disposed on a surface of the conductive particle; and the weight of the insulating particle as a whole is relative to The weight ratio of the above conductive particles exceeds 0.03 and is 0.25 or less. The conductive particles of the insulating particles according to claim 1, wherein the insulating particles are organic particles or inorganic particles, and when the insulating particles are organic particles, the weight of the insulating particles as a whole is relative to the conductivity. When the insulating particles are inorganic particles, the ratio of the weight of the insulating particles as a whole to the weight of the conductive particles is 0.08 or more and 0.25 or less. The conductive particles of the insulating particles according to claim 2, wherein the insulating particles are organic particles; and the ratio of the weight of the insulating particles as a whole to the weight of the conductive particles exceeds 0.03 and is 0.12 or less. The conductive particles of the insulating particles according to claim 2, wherein the insulating particles are inorganic particles; and a ratio of a weight of the entire insulating particles to a weight of the conductive particles is 0.08 or more and 0.25 or less. The conductive particles with insulating particles according to any one of claims 1 to 4, wherein the conductive particles have a substrate particle and a conductive portion disposed on a surface of the substrate particle. The conductive particles of the insulating particles according to claim 5, wherein a ratio of the total weight of the insulating particles to the weight of the substrate particles exceeds 0.086 and does not reach 0.600. The conductive particles with insulating particles according to any one of claims 1 to 4, wherein the conductive particles have a plurality of protrusions on a surface of the conductive portion. The conductive particles with insulating particles according to any one of claims 1 to 4, wherein the conductive particles have a substrate particle and a conductive portion disposed on a surface of the substrate particle; and the insulating particle as a whole The ratio of the weight to the weight of the substrate particles exceeds 0.086 and does not reach 0.600; and the conductive particles have a plurality of protrusions on the surface of the conductive portion. The conductive particles of the insulating particles according to claim 7, wherein the insulating particles have an average particle diameter larger than an average height of the protrusions. The conductive particles with insulating particles according to any one of claims 1 to 4, which are dispersed in a binder resin and used as a conductive material. The conductive particles with insulating particles according to any one of claims 1 to 4, wherein the first connection target member having the first electrode on the surface and the first connection member on the second connection target member having the second electrode on the surface thereof The electrode is electrically connected to the second electrode; and a space between a portion of the first connection member that does not form the first electrode, that is, a minimum width between electrodes, and a second connection target member that does not form the second portion The space of the portion of the electrode, that is, the minimum width between the electrodes is 20 μm or less. A conductive material comprising the conductive particles with insulating particles according to any one of claims 1 to 11, and a binder resin. A connection structure comprising: a first connection member having a first electrode on a surface thereof, a second connection member having a second electrode on a surface thereof, and a connection portion between the first connection target member and the second connection target member; the connection portion is formed of conductive particles with insulating particles according to any one of claims 1 to 11, or includes the above-mentioned insulation The conductive particles of the particles and the conductive material of the binder resin are formed; and the first electrode and the second electrode are electrically connected by the conductive particles of the conductive particles with the insulating particles. The connection structure of claim 13, wherein a minimum space between the electrodes, that is, a space in which the first electrode is not formed, and a portion in which the second electrode is not formed in the second connection member The space, that is, the minimum width between the electrodes is 20 μm or less.